LTC 101-2025 North Beach Quality and Park View Canal University of Miami Phase II ReportDocusign Envelope ID:C3B08E99-980B-4 408-A3EA-4A787 CE2279
M IAMI BEACH
OFFICE OF THE CITY MANAGER
LTC#
RECEIVED
MAR 1 0 2025
CITY OF MIAMI BEACH
OFFICE OF THE CITY CLERK
LETTER TO COMMISSION
TO:
FROM:
DATE:
SUBJECT:
Honorable Mayor Steven Meiner and Members of the City Commission
ne carp enter,cy vene er 1'~5gt#
March 7,2025
North Beach Water Quality and Park View Canal University of Miami
Phase II Report
The purpose of this Letter to Comm ission is to disseminate the most recent water quality study for
North Beach and the Park View Canal.The study was conducted by the University of Miami
(Attachm ent A),at the direction of the City Commission Resolution No.2023-32852.The City
Comm ission referred the report and presentation to the Land Use and Sustainability Committee
on February 3,2025,item C4 G,with the anticipation of being heard March 11, 2025.Dr.Helena
Solo-Gabriele,Ph.D.,P.E.is planning to provide the presentation.
The City of Miami Beach is committed to maintaining and improving the quality of its waterways
and pro tection of Biscayne Bay.The Administration continues to move forw ard with prioritized
im pro vem ents funded through City Commission approval to address water quality concerns related
to North Beach Water Quality and Park View Canal (PVC).The action plan includes above-ground
sanitation,below-ground infrastructure improvements,canal dredging design and permitting
evaluations and additional research conducted by Dr.Solo-Gabriele,water quality expert from the
University of Miami.The report notes that an improvement has been observed since short term
im provem ents such as air release valves and pipe lining were conducted in 2023.Despite the
im provem ents,the canal still has fecal indicator bacteria concentration that exceeds recreational
water quality standards established by the Florida Department of Health for ocean beach
standards for bathing.
The initial study,completed in 2023,highlighted that rainfall is the main predictor of poor water
quality in the canal,with sediments from the canal shoreline,the streets,and sediments in catch
basins and shallow groundwater entering the canal from the 81-acre catchment area to the east.
Despite rigorous sanitary sewer testing,the system including private connections is aging and
could not be ruled out.Sanitary sewer upgrades have been made including closed-circuit
television studies and lining the sewer pipes from 73 to 76 Street as well as rehabilitated manholes
where needed,including North Beach pump station wet well rehabilitations.Stormwater treatment
to reduce litter is underw ay by retrofitting the current gravity stormwater system with advanced
water quality treatment devices,in addition,the North Beach Town Center Neighborhood
Impro vem ent Project plans to address additional aging infrastructure.The 2023 study also
identified many additional sources contributing to degraded water quality,including exotic and feral
animal feces,the hom eless population,dog waste,litter,and leaking dumpsters in commercial
areas.
In addition to completed and planned infrastructure upgrades,the city has increased inspections
and serv ices.Code Compliance continues focusing on proactive patrols while enforcing the
cleanup of pet waste,Parks & Recreation continues its roaming patrols,and Environment &
Sustainability staff,alongside the Public Works Operations team continue to work with Homeless
Outreach on their increased routine site visits.Sweeping and hand litter collection continue on
Park View Island and additional pet waste dispensers were installed in high-traffic areas.
101-2025
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The new Phase II data collection by UM has been completed and was compiled and analyzed in
the form of a final report.The following was conducted as part of the study:
•Collected stormwater before catch basins (catch system under grate before basin)to
determine how much fecal bacteria is coming from the streets vs groundwater.
•Sampled groundwater directly utilizing direct push technology for samples of upper
groundwater to determine the background levels of fecal bacteria.
•Tested within catch basins with biomarker source tracking (i.e.bird,dog,human)to
determine how much fecal bacteria is coming into the system and from which source.
•Analyzed groundwater elevations to tie the elevation of the canal to groundwater,along
with a comparison to pipe elevations.
•Reviewed and updated the City's historical data with information and testing that has been
made available since the Phase I study concluded,from both Surfrider's Bluewater Task
Force and the City's datasets.
Phase II Study Results
Private Outfalls
A hotspot adjacent to the Park View Canal was discovered near the outfall from Biscayne Beach
Elementary School,where the levels were well above the detection limit and significantly above
levels observed at the Kayak Launch.The Administration has offered support to the school,
offering meetings and on-site visits,and has asked the Miami-Dade County Public Schools to
collaborate with the City to mitigate the elevated levels near the outfall.
Private property should continue to be investigated as sources of pollution to the Park View Canal.
However,this poses a challenge for the City of Miami Beach which does not have the authority for
enforcement of private stormwater systems maintenance.Private property owners should have
Class II stormwater permits with Miami-Dade County and properly maintain the system as to not
contribute to water quality degradation.
Genetic Markers
Additional testing was performed for genetic markers to determine the source of contamination
including human,dog,and bird fecal waste.While the groundwater had no levels of dog nor human
fecal waste,the bird marker was found in most samples of groundwater,stormwater,and canal
water,with the highest levels observed within the canal water.
It can be hypothesized that birds are a significant source of fecal waste interior to the PVC,likely
depositing fecal matter on the banks and shore of the PVC which is then washed in with the tides.
It is also possible that the waste from the canal backwashes into the groundwater,leading to the
detectable bird marker in the groundwater samples.
2 out of 11 samples showed dog marker and 2 out of 11 samples showed human marker in the
stormwater.This irregular presence of the dog and human marker in stormwater collected at the
street was believed to come from "aged"fecal waste,where the original fecal signal has been
degraded.The consistently high enterococci levels observed in stormwater at the street surface,
all obtained from aged dog and human sources,intermittent fresh dog and human sources,and
bird sources,emphasize that remediation efforts should focus on reducing enterococci in the
street-level stormwater runoff.
City efforts to improve the water quality in Park View Canal
Sanitary Sewer Improvements
Public Works completed $640,000 of Phase 1 Park View Sewer Trenchless Rehabilitation
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upgrades and sewer force main air release valve replacements. In addition,$2.5 million was
appropriated for the Phase 11 of the North Beach and Park View Extended Area project.The project
is 90%complete and invoiced.This scope included closed-circuit television studies,lining of sewer
pipes from 73"to 76"Streets,as well as the rehabilitation of manholes wherever needed. In
January of 2025,100%of sewer lining ,including all five (5)North Beach pump station wet well
rehabilitations were completed.Public Works also concluded citywide force main leak detection,
which results found zero leaks in the system.A new force main system will be installed as part of
the $70 Million,72"Street Community Complex project,which includes removing old lines that
can become a potential future source of contamination.
Stormwater Treatment
Public Works is adding stormwater treatment to existing stormwater outfalls.A consulting firm has
been contracted for the design of the stormwater treatment system,with hydrodynamic separators
planned to reduce trash and sediment discharge.The cost is $2.2 million and construction is
expected in late 2026.
The North Beach Town Center/North Shore D Neighborhood Improvement Project will have
significant water quality benefits by moving stormwater outfalls to new locations and meeting
today's water quality requirements.The City received a $10 million grant for the design and
permitting of the project,however,construction funding will be needed.The project will replace the
stormwater pipe network between 69th and 73rd Streets and include features like injection wells,
stormwater pump stations,and filtration systems.
Pursuing Dredging to Increase Flow/Flushing
Environment and Sustainability is implementing $500,000 funded for dredging design and
permitting to improve water exchange rates and remove sediment and marine debris from the
canal.The department contracted T.Y.Lin International to develop the construction documents
necessary for the project,which involves environmental regulatory agency-required bathymetric
and geotechnical surveys within the waterways.Bathymetric and geotechnical surveys are
complete and were compiled by the consultant's engineering team to conduct a flushing analysis.
The results of these evaluations are being carefully reviewed for desired water quality outcomes
and the appropriate next steps which may include application submittals to the regulatory
permitting agencies.Project mobilization is recommended to coincide with the hydrodynamic
separator installation to reduce sediment inputs into the canal following dredging.
Above Ground Sanitation
Public Works conducts hand crew and mechanical sweeping three times a week within Park View
Island.The Sanitation team hand crew also conducts detail cleaning once a week from 71 street
to 75 street.The City also installed five additional doggie bag dispensers in the area of 71 street
to 75 street to encourage proper disposal of pet waste and assist with above-ground cleanliness.
Overall,these efforts are expected to improve water quality in the PVC,though major investments
in infrastructure are still needed to achieve more significant improvements to be implemented in
the North Beach Town Center/North Shore D project.
New Recommendations
The new Phase II report highlighted many recommendations,with the full list in Chapter VI
(Attachment A). In addition to the current strategies for water quality,the Administration has
highlighted the following:
1.Address the stormwater and sanitary system at Biscayne Beach Elementary School in light
of the hotspots observed in groundwater and from the stormwater outfall.
2.Miami-Dade County should investigate private outfalls as sources of pollution to the Park
View Canal.
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3.More street sweeping in the North Beach watershed,which would require a new parking
program that limits parking on certain days to allow for more robust street sweeping.
4. Include smaller scale street sweepers in addition to the industrial scale street sweeping,to
ensure that the sediment accumulating in gutters and curbs can be cleaned.
5.Deep cleaning of grassy areas,gutters,and anyw here animal waste is seen and exploring
UV disinfection.
6. In addition to encouraging pet owners to pick up after their pets,staff recommends
designated pooper scoopers followed by possible environmentally friendly disinfection to
further clean up areas with visible feces and adding more pet waste stations.
7.Homeless population use of the canal and storm drains for waste was documented.
Additional attention should be given to this community as public access to sanitation
facilities is limited and extended hours should be explored.
8.Consider re-evaluating the fecal indicator bacteria standard used to determine recreational
safety;the standard used is for beach bathing,but the City can consider secondary
recreational usage standards for activities such as kayaking.The FDOH enterococci single
sample limit for recreational beach use is 70 MPN/100ml whereas the US EPA single
sample limit for enterococci for kayaking in calm water is 371 MPN/1 00ML.Due to the Park
View Canal's geometry and characteristic as a "canal within a canal within a bay"with
limited flushing,it may be immensely difficult to reach beach standards for bathing.
Beaches have higher standards due to the probability of ingesting water while recreating
for longer periods of time and also have significant water exchange rates ocean-side that
dilute pollution.
9.There are several recommendations to minimize loose trash.An updated educational
campaign can be developed targeted to North Beach on above-ground sanitation efforts
from the public to assist City efforts.This can include information on proper garbage
disposal for residents and businesses,anti-littering messaging,pet waste pick-up
importance,and sediment and erosion control best management practices for construction
sites or sidewalk disinfection procedures.
10. Improve shorelines to limit the erosion of sediments and transport of trash by runoff along
the shoreline.The City has received a federal appropriation agreement for $963K which
will be used towards the design of the North Beach Living Shorelines Project.
The Administration has welcomed the direction from the City Commission to complete the
additional study which has revealed additional insights and actions to help support current multi-
departmental efforts.For questions and comments regarding this memorandum,please contact
Amy Knowles,Chief Resilience Officer/Environment and Sustainability Director at
amyknowles@miamibeachfl.gov or Lindsey Precht,Assistant Director at
lindseypr echt@miamibeachflgoy.
Attachment A:Reportl
Assessment of Enterococci in Groundwater and
Stormwater at the Miami Beach Park View Canal
DRAFT REPORT
Version dated February 24,2025
Ayaaz (Johann)Amirali M.S.,Cristina Fayad Martinez M.S.,Aarohi Talati,
Diego Lopez Oranday,Larissa Montas Ph.D.,Isabela Puente,Rivka Reiner,Matthew Roca,
Helena Solo-Gabriele,Ph.D.,P.E.
University of Miami,Coral Gables,FL
Department of Chemical,Environmental,and Materials Engineering
with Microbial Source Tracking Contributions by
Maribeth Gidley,D.O.,Christopher Sinigalliano Ph.D.,and Robert Bremer
National Oceanic and Atmospheric Administration
Virginia Key,FL
Submitted to:
City of Miami Beach (c/o Lindsey Precht)
1700 Convention Center Drive
Miami Beach,FL 33139
tu
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TABLE OF CONTENTS
TABLE OF CONTENTS
EXECUTIVE SUMMARY
LIST OF ACRONYMS
CHAPTER I,MOTIVATION,OBJECTIVES,&BACKGROUND
1.1 Motivation and Objectives
1.2 Target Levels for Enterococci and Microbial Source Tracking Markers
1.3 General Conditions of the PVC
CHAPTER II,ANALYSIS OF HISTORICAL DAT A
II.I Analysis of Historical Enterococci Records Over Time
II.2 Source of Ambient Data
II.3 Relationships between Historic Enterococci Levels and Environmental Factors
CHAPTER III,ANALYSIS OF THE STORMWATER CONVEYANCE SYSTEM
III.1 Estimates of PVC Water Surface Elevations
III.2 Inundation of the Storm water Conveyance System
III.3 Sanitary Sewer System
CHAPTER IV,ANALYSIS OF ENTEROCOCCI IN GROUNDWATER,STORMWATER,
AND WITHIN THE PVC CANAL
IV.I Groundwater
IV.2 Stormwater
IV.3 Water from the PVC
IV.4 Combined Results from UM Samples
IV.5 Stormwater and PVC Data in the Context of the Literature
CHAPTER V,RESULTS FROM MICROBIAL SOURCE TRACKING
V.1 Sample Processing for MST
V.2 Results from MST Analysis
V.3 Correlations Among Enterococci and MST Measurements
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TABLE OF CONTENTS (Continued)
CHAPTER VI,OVERALL ASSESSMENT AND RECOMMENDATIONS
Vl.l Reduce Enterococci in Stormwater at Street Surface
Vl.2 Reduce Enterococci in Groundwater
Vl.3 Reduce Enterococci within the Stormwater Conveyance System
VI.4 Reduce Enterococci within the PVC
VI.5 Long-Term Comprehensive Stormwater Planning
VI.6 Summary and Recommendations
ACKNOWLEDGMENTS
REFERENCES AND PERTINENT LITERATURE
APPENDIX A,Historical Data (CMB and Surfrider)
APPENDIX B,Stormwater Infrastructure Detail
APPENDIX C,UM Sample Collection Timeline and Data Details
APPENDIX D,Laboratory Processing Details for MST and EnterolA Markers
APPENDIX E,Response to Written Comments from the Community
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EXECUTIVE SUMMARY
This study is a follow up to the University of Miami (UM)initial study conducted during 2022 aimed at
identifying the source of enterococci to the Parkview Canal (PVC)located in Miami Beach,Florida.This canal
has experienced elevated levels of fecal indicator bacteria including enterococci since monitoring began in
2019.The 2022 study concluded that the primary source of enterococci to the PVC was stormwater runoff
which was contaminated by waste deposited on surfaces that drain towards the PVC.In addition,the study
concluded that between storm events contaminated groundwater was also contributing enterococci to the PVC.
The prior study did not determine the source of groundwater contamination,whether it was contaminated from
stormwater runoff or by sanitary sewage,as samples were collected from the underground stormwater
conveyance system which receives both sources of water.
As a first step of the current 2024 study,available historical data collected by the City of Miami Beach (CMB)
and by Miami Surfrider were analyzed to determine whether remediation efforts initiated by the CMB since
2022 have resulted in a reduction in PVC enterococci levels.Remediation efforts included community outreach
to pet owners and homeless populations, increased intensity of street sweeping,enforcement of appropriate
solid waste handling and disposal,assessment and rehabilitation of sanitary collection and transmission system
to include lining of gravity pipe and manholes plus the replacement of air release valves within the sanitary
sewer system.Assessment and rehabilitation of sanitary system was prioritized in North Beach because of the
PVC water quality issues.Results showed that enterococci levels,although still high,did drop after remediation
efforts.This drop was observed from the CMB and the UM historical records.Of significance was that the
pattern observed earlier between storm events was not observed in 2024, indicating that groundwater was not a
primary source of enterococci to the PVC during 2024.Although improvements were observed between 2022
and 2024,they were not sufficient to bring the PVC to levels that are considered safe for recreational use.
Given that enterococci levels continue to be elevated,this current project aimed to identify the source of
enterococci contamination to the PVC by collecting and analyzing samples of groundwater and stormwater
separately,outside of the underground stormwater conveyance system.Groundwater was collected by drilling
temporary wells and stormwater was collected from the street surface during storm events.Samples were also
collected hourly over a 12-hour period within the PVC canal.All samples were analyzed for physical-chemical
parameters (temperature,pH,salinity,dissolved oxygen,and turbidity)and for enterococci by culture using the
most probable number (MPN)method.To determine the source of the enterococci for each of these waters,a
subset of samples (number of samples,n =78)was analyzed for five genetic markers.Four are microbial source
tracking markers (MST)targeting human,dog,bird,and gull fecal waste sources.The last genetic marker was
an Enterococcus species marker for comparing MST results (which do not test for viability)against the
traditional culture-based method of enterococci analysis used for regulatory purposes.
Results showed that enterococci by culture were extremely high.Most samples were above the 24,196
MPN/100 mL quantification limit.When sample dilutions were adjusted,samples also exceeded the 241,960
MPN/100 mL quantification limit.For groundwater,levels of enterococci were variable with values ranging
from below detection limits (<10 MPN/100 mL)to above the limit of detection (>24,196 MPN/100 mL).The
groundwater hot spot measuring above the detection limit led to investigations of the outfall from Biscayne
Beach Elementary School (BBE),which showed enterococci at levels (198,000 MPN/100 mL maximum)
significantly above levels observed at the Kayak Launch (9,800 MPN/100 mL maximum).The CMB is
currently working with Miami-Dade County Public Schools to mitigate the cause of the elevated levels of
enterococci at the BBE outfall.For samples collected hourly from the PVC,enterococci levels dropped
throughout the course of the day presumably because of solar radiation.The highest level (9,800 MPN/100 mL)
from the PVC was collected from the water's surface during the late afternoon and shortly after a small rain
event.
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Results from MST showed that groundwater had no quantifiable levels of dog nor human marker.The bird
marker was found in most samples (in groundwater,stormwater,and PVC water)with the highest levels
observed for samples collected from within the PVC.The general bird GFD MST marker was statistically
higher in the PVC (88,000 genomic copies (gc)per 100 mL)compared to the groundwater (400 gc/100 mL)and
stormwater (430 gc/100 mL).We therefore hypothesize that birds are a significant source of fecal waste
"interior"to the PVC.It is possible that birds along the banks of the PVC deposit fecal matter directly into the
PVC and along the shore which is then washed in during high tide.It is also possible that water from the PVC
backflows through the storm conveyance system into the groundwater resulting in detectable levels of bird
marker in the groundwater samples.In general seagull specific Gull2 MST marker was not found in most of the
samples,except for four stormwater samples,suggesting that the bird fecal input observed was predominantly
from other bird species during the period immediately preceding sample collection.
The distribution of the MST bird marker is contrary to what was observed for enterococci measurements,with
enterococci showing high and sustained levels in stormwater.Of significance was the intermittent quantification
of dog (11 out of 3 7 samples)and human marker (18 out of 3 7 samples)in stormwater collected at the street
surface.Given the intermittency of the observed dog and human markers,we believe that the sustained elevated
levels in stormwater came from "aged"fecal waste which may have lost the original fecal source signal (due to
die off of a different bacteria used for MST).
The consistently high enterococci levels observed in stormwater collected at the street surface (which may come
from sustained aged dog and human sources,intermittent fresh dog and human sources,plus bird sources),
emphasize that efforts should focus on reducing enterococci in street-level stormwater runoff.To augment
ongoing efforts of the CMB,we recommend "deep cleaning"of grassy areas,gutters and anywhere animal
waste is seen.In addition to industrial scale street sweeping,smaller scale street sweepers are recommended that
can be walked through gutters and curbs where sediments accumulate to provide more frequent and detailed
cleaning.In addition to encouraging pet owners to pick up after their pets,we recommend designated pooper
scoopers followed by possible disinfection to further clean up areas with visible feces.The area is also impacted
by populations (inclusive of homeless and others)who lack access to sanitary facilities.Consideration should
include augmenting access to sanitation facilities,especially during hours when public facilities are closed.
Until significant engineering stormwater treatment systems can be implemented,we believe that "deep
cleaning"and enhanced access to sanitation will be necessary to further improve the quality of the PVC.
Quick tum-around actions taken by the CMB to limit enterococci contamination have included its aggressive
program of education and outreach.The CMB has expanded its community outreach efforts through its
Constant Contact system through which updates are provided to the community and from which the City solicits
input from its residents.The CMB continues with the provision of extensive outreach services to the homeless
in the area,with education programs to minimize dog fecal waste throughout the stormwater catchment,and
with the management of non-native feral animals.Trash on streets continues to be minimized through street
sweeping,code enforcement,educational outreach,and clean up.The CMB is committed to minimizing the
leakage from trash bins through education campaigns aimed at commercial business owners by emphasizing the
importance of covers on trash bins and frequent trash pickup.
For the long term,we recommend that the flushing capacity of the PVC be improved through the removal of
trash and debris that inhibits water flow and tidal flushing.We also recommend upgrading the stormwater
conveyance system to include trash removal and the treatment of the first flush of stormwater,which is
currently standard among stormwater conveyance systems.The CMB has already taken immediate action on
these long-term items including plans for dredging the PVC to improve water circulation and have contracted a
consulting firm for the design of the stormwater treatment system.To date the work toward dredging has
included the completion of the bathymetric analysis of the PVC in preparation for soliciting bids from canal
dredging companies.The timeline includes the release of bid documents and technical specifications by January
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2026 with project mobilization by June 2026 and completion by January 2027.In terms of stormwater
treatment,the CMB,through $200K requested and funded by the city commission,has contracted the design
and permitting for the addition of hydrodynamic separators to the storm water conveyance system as a means of
reducing trash and sediments discharged to the PVC.The permit will be submitted by March 2025.
Additionally,the CMB has been awarded a $I OM Florida Resilient Grant for the design and permitting of the
North Shore D Neighborhood Improvement project)which includes a proposed stormwater conveyance system
that will replace the existing stormwater pipe network between 69"and 73""Streets.The stormwater
conveyance system is to include injection wells (to treat the first flush)and two stormwater pump stations fitted
with bar racks,vortex water quality structures,and upflow stormwater cartridge filters.The completion target
date for this larger project is 2028.
Specifically,to address sanitary sewage,as part of Phase 2 North Beach and Park View Extended Area,more
than $2.5 million of upgrades have been invested to line 90%of the sewer lines from 73 to 76 Street,
rehabilitate manholes,rehabilitate a pump station,and plan for a force main replacement.As of mid-January
2025,all the Phase 2 infrastructure upgrades have been completed.Additionally,the CMB has conducted city
wide force main leak detection.The leak detection tests concluded no leaks in the force main transmission
system.As part of the planned $70M 72"Street Community Complex the intense wastewater infrastructure
(within a secondary groundwater hotspot area)will be bypassed by a new force main system.The old lines will
be abandoned eliminating the existing sanitary sewer force mains in the area as a potential source in the future.
This project will be submitted to the Design Review Board of the CMB during early 2025.
Additionally,as evidenced by the exceedances detected in the Biscayne Beach Elementary outfall and
groundwater,private property should continue to be investigated as sources of pollution to the Park View Canal.
However,this poses a challenge for the City of Miami Beach which does not have the authority for enforcement
of private stormwater systems maintenance.Private property owners should have Class II stormwater permits
with Miami-Dade County and properly maintain the system as to not contribute to the PVC water quality
degradation.
Overall,the mitigation plan for the stormwater conveyance and sanitary sewer systems should provide
improvements to water quality in the PVC.Some short-term improvements have been observed;however,the
levels are still considered excessive.To make more substantive improvements,major investments in the
stormwater infrastructure are needed which the CMB has initiated by procuring funds for design and permitting,
which is the necessary first step to implementation.
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LIST OF ACRONYMS
AOML:Atlantic Oceanographic and Meteorological Laboratory
BAV:Beach Action Value
CFU:Colony Forming Units
CMB:City of Miami Beach
COV:Coefficient of Variation
EPA:Environmental Protection Agency
FDEP:Florida Department of Environmental Protection
FDOH:Florida Department of Health
FIB:Fecal Indicator Bacteria
gc:Target Gene Copies
GIS:Geographic Information System
KL:Kayak Launch
KLW:Kayak Launch Waterway (used interchangeably with PVC)
MF:Membrane Filtration
MPN:Most Probable Number
MST:Microbial Source Tracking
NOAA:National Oceanic and Atmospheric Administration
PCR:Polymerase Chain Reaction
POR:Period of Record
PVW:Parkview Canal Watershed
PVC:Park View Canal
PVI:Park View Island
PVP:Park View Park
QMRA:Quantitative Microbial Risk Assessment
RBT:Risk Based Threshold
SFWMD:South Florida Water Management District
STV:Statistical Threshold Value
TKN:Total Kjeldahl Nitrogen
TPTV:Ten Percent Threshold Value
UM:University of Miami
US EPA:United States Environmental Protection Agency
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CHAPTER I
MOTIVATION,OBJECTIVES,AND BACKGROUND
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CHAP TE R I
MO TIV A T IO N ,O BJECTIVE S,AND BACK G RO UND
This chapter focuses on describing the motivation,objectives (Section I.l)and the project background for this
study.including target levels for enterococei and fecal coliform,background information for MST (Section I.2),
and general conditions of the Park View Canal (Section I.3)
1.1 MOTIVATION AND OBJECTIVES
Stormwater from the Parkview Canal Watershed (PCW.Figure I.I)within the City of Miami Beach (CMB)
contributes large pulses of fecal bacteria,known as enterococei,at levels thousands of times higher than
regulatory guidelines for recreational use of waterways to its receiving water body (Parkview Canal.PVC).As a
result of the stormwater contamination,and the excessive bacteria levels,the adjacent PVC and the kayak
launch (Figure I.2) from its park has been closed to the public since 2019.This closure represents a lost
resource for the community.
Our prior research through the University of Miami (UM)and supported by the CMB (Montas et al. 2023).
showed that stormwater from the PCW is contaminated with high levels of enterococci and flows into the PVC,
or is discharged to groundwater,with little to no treatment.The most extreme contamination was observed
during storm events,with impaets also observed between storm events,presumably due to stormwater
contamination of groundwater.Therefore,a strong need exists to document stormwater quality and groundwater
quality.
Figure I.I:Park View Canal (dark blue)and Park View Watershed (cyan blue).The areas outlined in cyan blue
contribute storwater towards the PVC.Close up of kayak launch area (yellow square)shown in Figure I.2.
Base image from Google Earth (January 2023).
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To assess stormwater and groundwater quality,the objectives of this study were:
•Update the Analysis of Regular Enterococci Monitoring Data.The CMB and Surfrider collect data
on a regular basis from the PVC at the Kayak Launch.Our objective was to statistically analyze this data
through the end of September 2024 to document whether enterococci levels have declined over time as
the CMB has enhanced mitigation measures.
•Evaluate PVC Surface Water Elevations Relative to Groundwater Elevations.The prior UM study
conducted in 2022 suggested that contaminated groundwater contributed to the PVC when hydraulic
gradients were in favor of this occurrence (when the elevation of water in the PVC was lower than the
groundwater elevation).This occurrence could not be evaluated quantitatively because the elevation of
the PVC water was unknown.In this current 2024 study,a benchmark was installed from which the
PVC surface water elevations could be determined allowing for the comparison of PVC water elevations
relative to groundwater.This information was then used to analyze the historical enterococci data to
determine if enterococci levels were correlated with the hydraulic gradients.
•Evaluate Elevations of the Stormwater Conveyance System.The PVC surface water elevations and
the groundwater elevations were also used to evaluate the extent and periods of inundation of the
stormwater conveyance system.Such an evaluation provided information about whether the stormwater
conveyance system skims the upper surface of the groundwater,providing for a direct connection
between the PVC and,potentially,contaminated groundwater.
•Collect and Analyze Shallow Groundwater Samples.Shallow groundwater was implicated as a
source of enterococci between storm events during the 2022 UM study.Samples of groundwater were
collected from the catchment area using direct push technology and analyzed for enterococci and for
physical-chemical parameters (water temperature,pH,salinity,dissolved oxygen,and turbidity).
Sample splits were archived for Microbial Source Tracking (MST)Analysis.
•Collect and Analyze Stormwater Samples.Stormwater runoff was implicated as the primary source of
enterococci during the 2022 UM study.The stormwater was believed to contribute directly during
storms and indirectly by contaminating shallow groundwater.To confirm stormwater as a source of
enterococci,samples were collected from storm water before or as it enters the catch basins.Similar to
the groundwater samples,sample splits of stormwater were archived for MST Analysis.
•Collect and Analyze Water from the PVC.The study focused on evaluating the sources of enterococci
to the PVC.Samples from the PVC were collected to assess trends over time and depth.Similar to the
above,sample splits of PVC water were archived for MST Analysis.
•Measure Source Tracking Markers.A subset of the samples collected were analyzed for four MST
markers.MST markers are specialized molecular analyses that further identify which species (humans,
dogs,birds and/or gulls)are contributing fecal waste to a sample.MST was used to assess potential
contributions of enterococci from humans,dogs,birds and gulls to groundwater,stormwater,and to the
PVC.A fifth genetic marker analysis was included in this study to measure Enterococcus (molecular
based representation of enterococci)to provide a comparison between the culture-based method
(provides data in units of MPN)versus the molecular-based method (provides data in units of gc).
11
Figure I.2:Kayak launch location.Located within the Parkview Island Park northwest of the intersection of
Dickens and 73rd Street,Miami Beach,FL.(GPS:25°51 31.20"N.80 07 33.00 W for the Launch)
1.2 TARGET LEVELS FOR ENTEROCOCCI AND MICROBIAL SOURCE TRACKING MARKERS
I.2.a Target Levels for Enterococci
Enterococci is a group of bacteria species recommended by the U.S.Environmental Protection Agency (US
EPA)as the fecal indicator bacteria (FIB)to assess the microbiological safety of marine recreational waters.It
is used to assess the potential relative risk of gastrointestinal illness from incidental ingestion.The largest
amount of incidental ingestion generally occurs during primary contact which is full body contact activities
(such as swimming,surfing,and water skiing)(US EPA 2022).Incidental ingestion also occurs during
secondary contact recreation such as kayaking and fishing.Secondary contact is presumed to be associated with
smaller amounts of incidental ingestion so standards for secondary contact are less stringent than for primary
contact.Regulatory levels for FIB are set based upon type of contact (primary or secondary)and levels of
estimated gastrointestinal illness (generally from 19 to 36 illnesses per 1000 people exposed)as determined
from epidemiologie studies.
In Florida,regulatory limits for FIB in recreational waters are based upon the guidelines established by the US
EPA,with two State agencies setting regulatory limits:the Florida Department of Health (FDOH)and the
Florida Department of Environmental Protection (FDEP).Both agencies base their regulations on the
distributions focused on estimated illness rates of 3 6 per 1000 persons exposed.The FDOH,through the Florida
Healthy Beaches Program,assumes primary contact or full body contact (swimming)and establishes beach
advisories for recreational bathing beaches through a centralized reporting website that lists a recreational water
as good,moderate,or poor quality (See:floridahealth.gov/environmental-health/beach-water-
quality/index.html).Good quality beach water is defined as enterococei levels less than 36 enterococci per 100
mL,moderate quality as levels between 36 and 70 enterococci per 100 mL, and poor quality as levels exceeding
70 per 100 mL.Beach "advisories"are issued when two consecutive samples exceed 70 per 100 mL.The value
of 70 per 100 mL corresponds to the US EPA recommended beach action value (BAV)which is a more
12
conservative estimate for beach management decisions.The BA V of 70 enterococci per 100 mL corresponds to
the 75"percentile of the enterococci distribution (US EPA 2012)for waters to meet an acceptable illness rate.
Similarly,the FDEP also has guidelines established for enterococci.The FDEP regulates surface waters of the
state according to their designated uses.The surface waters of the state are separated into one of six classes.
The classes that most closely align to the current uses of the PVC are Class III and Class III-Limited (See,
floridadep.gov/dear/water-quality-standards/content/surface-water-quality-standards-classes-uses-criteria).
These are defined as:
•Class III:Fish Consumption,Recreation,Propagation and Maintenance of a Healthy,Well-Balanced
Population of Fish and Wildlife
•Class III-Limited:Fish Consumption,Recreation or Limited Recreation,and/or Propagation and
Maintenance of a limited population of fish and wildlife.
The bacteriological criteria are the same for both classes listed above (F AC 2016).The criterion is listed in the
Florida Administrative Code as,"Most Probable Number (MPN)or Membrane Filtration (MF)counts shall not
exceed a monthly geometric mean of 35 nor exceed the Ten Percent Threshold Value (TPTV)of 130 in 10%or
more of the samples during any 30-day period.Monthly geometric means shall be based on a minimum of 10
samples taken over a 30-day period."The 130 corresponds to 90%percentile of the US EPA statistical
threshold value (STY)of the enterococci distribution,which is less conservative than the BA Vs.
A summary of the threshold values as established by the FDOH,FDEP,and US EPA is given by Table I.1.
When evaluating enterococci levels based upon single sample analyses,the general practice has been to use a
threshold value of 70 per 100 mL to designate the quality of a beach site (FDOH 2024 ).For subsequent
discussion purposes,the value of 70 will be used as the target threshold for assessing the microbial quality of
the PVC.However,the CMB may consider other acceptable levels consistent with secondary contact uses,such
as kayaking (calm versus turbulent waters)and fishing,which can potentially raise the threshold levels to 371
and 391,respectively.Given the intended use of the kayak launch and the calm waters within the PVC,a target
value of 370 MPN/100 mL may be considered as a future health-based guideline level once the levels within the
PVC fall consistently below this level.
Table:1.1:Target Guideline Levels for Enterococci as Listed by the FDOH,FDEP,and U.S.EPA
Agency
FDOH •Good quality<36 per 100 mL
Beach Recreational Standards •Moderate quality between 36 and 70 per 100 mL
(Primary Contact,Swimming)•Poor quality >70 per 100 mL (Beach Action Value)
FDEP •Geometric mean<36 per 100 mL,
Class III standards (Recreation)•10%of samples within a 30-day period <130 per 100 mL
U.S.EPA • Geometric mean<36 per 100 mL
(Primary Contact,Swimming)•10%of samples <130 per 100 mL
U.S.EPA •Geometric mean <45 per 100 mL
(Kayaking in turbulent waters,with •10%ofsamples<164per l00mL
capsizing)
U.S.EPA •Geometric mean <100 per 100 mL
(Kayaking in calm waters,no •10%of samples<371 per 100 mL
capsizing)
U.S.EPA •Geometric mean <106 per 100 mL
(Fishing)•10%of samples<391 per 100 mL
13
1.2.b Differences in Viability of Enterococci Measurements by Culture and the Measurements by qPCR
Accepted methods by the regulatory community for measuring enterococci require the counting of viable (live)
cells within a known volume of water sample.The live culture method used in the current study and by the
CMB and Surfrider,is based upon a Most Probable Number (MPN)enumeration using a chromogenic
substrate.The chromogenic substrate used by all groups is the commercially available "IDEXX Enterolert"
assay.The chromogenic substrate method is based upon adding an enzyme or nutrient indicator to the water
sample.After incubation of the water sample the live enterococci in the water sample will consume the enzyme
releasing a fluorescent dye into the water that can be seen under ultra-violet light.Enumeration is accomplished
by separating the sample into individual wells which can then be counted for positive fluorescence.Statistical
methods are then used to estimate the Most Probable Number based upon the probability of a viable cell being
caught in the number of positive (or fluorescing)wells.Because the method requires the grown of the
enterococci,these measurements provide confirmation that the target bacteria are still viable (capable of
metabolism,growth,and reproduction).
The measurements of microbial source tracking (MST)genetic markers and the general enterococci marker
differ from those for live culture enterococci measurements.First,the measurements of the genetic markers are
based upon extracting DNA from the total population of microbial organisms in an environmental sample.This
multi-organism environmental DNA extract is abbreviated here as "eDNA".The eDNA contains all types of
DNA from all sources.For this study we targeted a suite of fecal bacteria genetic markers that are found
exclusively in humans (called "HF183"),in dogs (called "DG3"),in birds (called "GFD"),and in gulls (called
"Gull2"),which are specific to each type of animal,plus the general enterococci genetic marker called
"Entero 1 A"for all enterococci sources.Each type of MST assay DNA target marker has a specific and unique
sequence of the basic building blocks of DNA called nucleotides (i.e.,DNA target sequences)that are specific
to particular species and/or strains of fecal bacteria that are only found in the gut microbiome of that particular
animal host.The DNA target sequences are then replicated from the eDNA extracted from the environmental
samples by a process called amplification through Polymerase Chain Reaction,PCR.Amplification through
PCR proceeds through repetitive cycles of heating and cooling until there is enough target sequence (specific to
fecal bacterial DNA from dog,human,bird,gull,or to general enterococci species DNA)to detect by the
instrumentation.In the case of MST,this is done in a quantitative fashion on specific instruments in a process
called "real-time PCR"or "quantitative PCR"(qPCR)that can measure and calculate the original concentration
of the specific DNA target sequence in the environmental sample that is being measured.
During the analysis process,total microbial cells from a water sample are collected onto a membrane filter,then
the cells on the filter are broken open (lysed)which releases the entire eDNA content of all the bacteria on the
filter,which is then purified and analyzed by qPCR for the concentration of the specific diagnostic gene that is
chosen to be measured.This,of course,kills the microbial cells in the analysis process since the cells are being
broken open to release their DNA.Therefore,the qPCR process,used in MST,measures a fundamentally
different population of cells than the ones measured by the live culture growth methods used for regulatory
purposes.The live culture methods measure only cells that are alive and capable of reproduction.The qPCR-
based methods measure the specific DNA signal from each of the targeted specific types of cells being
measured,regardless of whether those cells were alive or dead at the time of collection.Therefore,
amplification of any genetic marker by qPCR does not indicate whether the bacteria that hosted the DNA
is still viable.This is a fundamental difference between the live culture assays that are used for regulatory
purposes versus assays based upon qPCR.
1.2.c Differences in Persistence of Enterococci Measurements versus MST Markers
The gut of warm-blooded animals consists of a wide array of microbes.Enterococci,one of the groups of
bacteria found in high abundance in the gut of many animals including humans,is the target group
14
recommended by the state and federal agencies (as listed in the prior section)for routine monitoring of
recreational waters to evaluate safety from fecal waste contamination.It consists of several species of bacteria
including the species of Enterococcus faecalis,E.faecium,E.avum,E.gallinarum,E.casseliflavis,and E.
durans.One of the drawbacks of using enterococci is that there are sources of enterococci in the environment,
in addition to fecal sources.Enterococci are known to survive outside of the gastro-intestinal tract (Wright et al.
2009).They can inoculate an environment (including soils,sediments,plant surfaces,biofilms on debris,and
biofilms on hardened urban infrastructure such as concrete gutters,storm drains and conduits,etc.).Depending
upon the environmental conditions,enterococci can persist for long periods of time and even multiply
(Desmarais et al.2000).Enterococci can thus also be present in the environment without any recent fecal
contamination events,and its detection in the environment by either live culture or qPCR might also be due (at
least in part)to persistence from a historic contamination event in the past (e.g.,a prior sewage leak).It is
generally accepted that enterococci from legacy contamination may not represent the same level ofrisk from
fecal pathogens as from a more recent contamination event.
Total enterococci measured by qPCR assays target unique gene sequences (encoded in the 23S ribosomal RNA)
found in most species of fecal enterococci.Since it is measuring enterococci which persists in the environment,
the qPCR measurements of the EnterolA marker are subject to the same persistence and possible environmental
regrowth issues as enterococci measured by live culture.Since the qPCR is based upon DNA measurements of
enterococci,both live and DNA from non-viable bacterial cells will be detected using this method.Differences
in the trends between enterococci by chromogenic substrate versus by qPCR are likely due to differences in the
relative levels of non-viable enterococci which are measured only by qPCR.
In this study,microbial source tracking (MST)markers specific to human and dog sources of fecal waste were
based upon the measurement of a specific gene (same as DNA target sequence but specifically references a
short sequence of DNA)within the bacteria genus Bacteroides.The unique gene marker for strains of
Bacteroides fecal bacteria that are found exclusively in humans is called "HF183",and the unique gene marker
for strains of Bacteroides found exclusively in dogs is called "DG3".Both are encoded within a specific part of
the bacterial genome called 16S ribosomal RNA.Bacteroides are bacteria that are obligate anaerobes:they can
survive exposure to oxygen for a limited time but cannot grow in the presence of oxygen.They do not survive
under prolonged aerobic conditions and cannot reproduce under aerobic conditions.Bacteroides will die
relatively quickly upon release into aerobic environments such as the water column (typically within a period of
a few days to a few weeks,depending upon environmental circumstances).
For birds,the "GFD"gene marker was measured (also encoded in the 16S ribosomal RNA)within specific
strains of fecal bacteria from the genus Helicobacter that are found exclusively in birds.These bird-specific
Helicobacter strains are common gut bacteria in a wide variety of many different types of birds.He/icobacter
can survive under both aerobic and anaerobic conditions,and so it tends to survive in the environment longer
than the Bacteroides.In this study we also measured specifically for a subset of the bird population,seagulls.
The seagull host specific fecal marker called "Gull2"targets the 16S ribosomal RNA gene of the bacteria
Catellicoccus marimammalium.This C.marimammalium species was first identified as an opportunistic
pathogen of marine mammals but is actually a common normal gut bacteria specific to seagulls and terns (but
may also sometimes be found in certain other seabirds and waterfowl such as pelicans,Canadian snow geese,or
even some coastal pigeons depending upon their feeding,scavenging,or co-nesting behavior with seagulls).
The Catellicoccus marimammalium Gull2 marker typically has a longer environmental persistence than the
human HF183 or dog DG3 but may be shorter than that typical of the Helicobacter GFD marker in the water
column.Catellicoccus grows best under increased carbon dioxide and reduced oxygen,which is consistent with
the intestinal environment of birds,but it does not grow as well under full outdoor aerobic conditions.
In terms ofrelative persistence,the bird MST host bacteria are believed to persist longer than the human and
dog MST host bacteria,with the human and dog MST markers being lost quickly due to the inability of the host
15
bacteria,Bacteroides,to survive in an aerobic environment.Therefore,the host bacteria that survive and persist
the longest (and can possibly multiply in the environment)are enterococci which can be measured by live
culture or by qPCR Entero 1 A marker.The next most persistent bacteria are the Helicobacter which carry the
markers (GFD)for the general bird marker.Next are the Catellicoccus bacteria which carry the gull marker
(Gull2),followed by the Bacteroides which are the weakest and carry the human (HFI 83)and dog (DG3)
markers.
1.2.d Target Levels for Enterococci and MST
The differences between viability and in the persistence of the gene carried by the host bacteria used for
measurements,makes it difficult to compare target levels between viable enterococci (used for regulatory
purposes)and the qPCR-based enterococci and MST markers.Regardless of these differences,attempts have
been made to establish equivalent Risk Based Thresholds (RBT)among the different methods (Tables 1.2 and
I.3).As a reminder from Section 1.2.a,the regulatory threshold for enterococci for full-body contact
(swimming)is 70 MPN/100 mL which corresponds to a 75%probability ofless than 36 gastrointestinal
illnesses among individuals exposed.
The US EPA has established a BAV for the qPCR EnterolA assay of 1000 gc/100 mL (US EPA,2012b,page
44)which corresponds to full-body contact and considering an RBT of 36 illnesses per 1000 exposures.The
State of Florida has accepted this recommended BAV for enterococci qPCR of 1000 gc/l00mL for those
counties and managers that may wish to use it to supplement swim advisories in addition to the culture-based
enterococci BAV of 70 MPN/l00mL for live enterococci.However,the qPCR specific BAV for enterococci is
not currently promulgated as a required regulatory criterion in Florida.It currently serves as an optional
guidance for beach management advisories.To the best of our knowledge,no beach managers in Florida are
currently using the enterococci qPCR option for beach advisories.
The RBT recommended for human marker (HF183)in water is 525 gc/100 mL from single-grab samples (when
no other fecal source risks are present).This RBT is based upon an assumption of 32 illnesses per 1000
exposures.This RBT has been proposed by researchers and has not been adopted by the State.We are not aware
of any RBT based upon the dog marker (DG3).Since humans share the most diseases amongst other humans,
the threshold for the MST human HF 183 marker can be considered an upper bound in comparison to the
threshold level for the dog DG3 marker.
There are no current RB Ts determined yet for public health impacts from specific concentrations of general bird
(GFD Helicobacter)marker in water,but there are already such RBT determinations for specific concentrations
of a seagull marker (Catellicoccus)in water as computed by researchers (Boehm and Soller 2020).In this study,
we have used these RBT values based upon seagulls to suggest potential levels of risk from exposure to the
more general bird GFD Helicobacter marker exposure in water for possible human health impacts.In the
absence of a human source,the RBT for the gull marker is computed as 200,000 gc/100 mL.Researchers have
also determined combinations of fecal contamination from gulls and humans together cumulatively.Lower
levels of human fecal waste have much greater risk when there is also fecal waste from other sources,such as
bird,present simultaneously in the same water body.The combination for human and gull markers that are
associated with excess risk (Boehm and Soller 2020)are given in Table 1.2 below.As per our understanding,
the bird-related RBTs have not been adopted by the State.
16
Table I.2:Simplified comparison between recommended threshold levels and enterococci and MST markers
analyzed in this study.Thresholds are calculated to equate to a projected illness rate of either 32 or 36 illnesses
per 1000 exposures for full body contact with water. See following table (Table 1.3)for a more thorough and
detailed explanation of the meaning of each target and their basis of comparison.
Target Purpose Measurement Persistence in Recommended Risk Based Reference
Environment Threshold Level for
Swimming
70 MPN/1 00mL for 36 -FDOH regulatory
Identify waters By culture so must Long and may illness/1000 exposures -EPA 2012
Live Enterococci impaired by fecal recreational water
waste be viable regrow (60 MPN/100 mL for 32 quality criteriaillness/1000 exposures)recommendations
Identify waters 1000 gc/1 00mL for 36 -EPA 2012
Entero 1 A marker of impaired by fecal By PCR so viability Long illness/1000 exposures recreational water
general Enterococci unknown (640 gc/l00mL for 32 quality criteriawasteillness/1000 exposure)recommendations
HF 183 marker of Identify human 525 gc/100 mL (for 32BacteroidesShort Research paper
'human)waste illness/1000 exposure)
DG3 marker of Identify dog waste Short Not Determined Research paperBacteroides(dog)
GFD marker of By PCR so viability Research paper based
Helicobacter Identify bird unknown Medium Not Determined upon Catellicoccus
general birds)waste seagull marker
Gull2 marker of 200,000 gc/100 mL
Catellicoccus (gull)Identify gull waste Medium (for 32 illness/1000 Research paper
exposure)
Combinations of human and gull marker genes equating to 32 illnesses/1000 exposures
1 HF183 Short 22,500 gc/100 mL (gull)
7 HFl83 10,000 gc/100 mL (gull)
30 HF183 Human and gull By PCR so viability (persistence of 3,000/100 mL (gull)
70 HF183 combinations unknown combination is 1,000/100 mL (gull)Research paper
120 HF183 driven by the 300/100 mL (gull)
370 HF183 HF183)1/100 mL (gull)
17
Table 1.2:Detailed comparison between recommended threshold levels of enterococci and MST markers analyzed in this study--Target Purpose Measurement Persistence in Recommended Risk Based Threshold Level for References
Environment Human Swimm ing'?
Live enterococci (official Identify waters By culture.Long (multi-year)and BAY of70 MPN or CFU/100 mL for viable Method:"IDEXX Enteroler"
regulatory method)potentially impaired by Cells must be may even regrow.cells from single-grab samples.Risk=36 or EPA Method 1600"(US
fecal waste,issue viable (can Testing takes more than illnesses/1000 exposures.Adopted by the State EPA,2009).
exposure warnings metabolize,24 hours for results.of Florida.BAY:(US EPA,2012b).
grow,and
reproduce)
"EnterolA"Total general Identify waters ByqPCRof Long (multi-year)and BAY of 1000 gc/I 00 mL from single-grab Method:"EPA Method 1611"
enterococci (live and dead)potentially impaired by eDNA,so may even regrow.May samples.Risk=36 illnesses/1000 exposures.(US EPA,2012a).
(alternate official regulatory fecal waste,issue viability is be tested more rapidly N ot adopted bv State.Mav optionallv be used BAY:(US EPA,2012b).
method)exposure warnings.unkn own .than by culture methods,to supplement advisories.
(Measures both may be combined with
live and dead other genetic tests.
"HF183"gene marker in human-Identify human fecal cells)Short (typically days to 525 gc/100 mL from single-grab samples Method:"EPA Method 1696"
host-specific Bacteroides waste -track fecal only a few weeks)(when no other fecal source risks are present).(US EPA,2019).
contamination to human Risk=32 illnesses/1000 exposures.Not RB T:(Boehm &Soller,2020).
sources such as sewage,adopted by State.
septage,illicit dumping,
etc.
"DG3"gene marker in dog-host- Identify dog fecal waste Short (typically days to Risk Based Thresholds for DG3 marker have Method:(Green et al., 2014).
specific Bacteroides -track fecal pollution only a few weeks)not yet been determined,and we are not aware RB T:No consensus for DG3
to potential terrestrial of any studies yet that suggest what level of thresholds.For this study we
run off sources such as human exposure risk to DG3 might be.Humans arbitrarily suggest that>10,000
stormwater,tidal and dogs share a wide range of pathogens,so copies/100 mL might be
flooding,etc.risk is possible.Not adopted by State.considered a risk.
"Gull2"gene marker in seagull-Identify seagull/seabird Medium (a few weeks) 200,000 gc/lO0mL from single-grab samples Method:(Sinigalliano et al.
host-specific Catellicoccus fecal waste -track fecal when no other fecal sources are present.22,500 2013).
marimammalium pollution to seabird gc/100 mL if 1 gc/l00mL human HF183 is RB T:(Boehm &Soller,2020).
inputs,including direct present.Risk=32 illnesses/1000 exposures.
deposition,runoff,Not adopted by State.See prior table for RB Ts
stormwater,etc.of combinations of gull+human markers.
"GFD"gene marker in Identify bird fecal waste Medium (a few weeks,RB Ts for GFD general bird marker have not Method:(Green et al.,2011)
Helicobacter fecal bacteria -track fecal pollution usually less than a yet been determined.We suggest for this study,RB T:Boehm &Soller,2020
found in most birds.(Note:to bird inputs,including month)to consider an arbitrary use of the Gull risk for Gulls.
general composite for total birds direct deposit to water thresholds for GFD as well,in consideration of
-but some birds may represent bodies,as well as the RB T for seagull Cate//icoccus fecal
more risk than others)runoff,stormwater,etc.bacteria.Not adopted by State.
1 The recomm ended "Beach Action Values"(BAV)are regulatory recommendations for triggering public health warnings from single-grab sample results.The BA Vs are guideline values
recomm ended by the US EPA to the states.The BAVs become enforceable when the States adopt them through statutes.
2 Risk Based Thresholds (RB T)are based upon either actual epidemiological studies of human exposure or upon Quantitative Microbial Risk Assessment (QMRA)predictive computer modeling of
human illness risk from exposure.Measurements of the targets greater than these RB Ts are estimated to have significant illness risk for human health outcomes.Note that these are not the regulatory
criteria for declaring impaired waters legal status,but rather guidelines for issuing public warnin gs as estimated within the research literature.
18
1.3 GENERAL CONDITIONS OF THE PVC
The PVC resides within the degraded northern Biscayne Bay (BBTF 2020).Degradation of Biscayne Bay has
been attributed to concentrated freshwater inputs at canal inlets to the bay which erode sediments,carry pulses
of nutrients that encourage algal blooms,and contribute towards seagrass die offs.In addition to lying within a
degraded Bay area,it suffers from restrictions to natural water flows.Tidal flushing from the Atlantic Ocean to
northern Biscayne Bay is provided through Baker's Haulover Inlet located 3 miles to the north and Government
Cut located 6.6 miles to the south (Figure I.3).Flushing is further restricted through its lack of direct connection
to the bay.The PVC is connected to a network of waterways that run north to south (Tatum,Biscayne Point,
and Normandy N-S Waterways)and east to west (Normandy E-W Waterway) (Figure 1.4).Most of the
waterways in this network have direct access to Biscayne Bay,however the PVC does not.The PVC is unique
in that it is a waterway embedded within a waterway which allows for the accumulation of the FIB and is
known to be a common symptom for waterways with limited flushing (Donahue et al.2017,Kelly et al.2018).
Other waterway characteristics include its relatively shallow depth,its numerous bends,and the mangroves and
shallow banks along its edge which have been shown to allow for FIB persistence and growth (Desmarais et al.
2002).
In addition to the lack oflimited flushing of the PVC,the area receives a considerable amount of storm water
runoff.It receives the entirety of the stormwater runoff from Parkview Island to the west (18.7 acres or 75,700
m2)as all storm water outlets on the island flow towards the east.It also receives stormwater runoff from a
considerable area to the west (62.6 acres or 253,400 m2)extending from the canal to Collins Avenue between
72 and 77 Streets.The size of the PVW catchment area is estimated at 81.3 acres (329,000 m2).Overall,
Parkview Island represents 23%of the area,and the area to the east on the main Miami Beach barrier island
represents the remaining 77%of the area.
Additionally,the entire watershed area is highly urbanized with a considerable underground infrastructure
designed to carry stormwater and sanitary sewage.The stormwater conveyance system is old (portions are over
80 years old)and designed prior to modern requirements for treatment of the first flush of stormwater.The
sanitary sewer system consists of two primary systems (gravity and force mains).The sanitary sewer systems
are of variable age and,although inspected,lined,and monitored,continue to be considered as a possible source
of enterococci.More details about the stormwater conveyance and sanitary sewer systems are provided in
Chapter III of this report.
Monitoring of the PVC by the CMB began in April 2019 as part of a storm water management program designed
to inform decision-making.At the time during 2019,CMB was in the process of identifying priority areas
within Miami Beach for possible installation of stormwater pump and treatment stations.At other locations,the
CMB has installed stormwater pump stations fitted with treatment systems designed to remove trash and grit
(via vortexer).However,such systems have not yet been installed to treat the stormwater within this catchment.
Since April 2019 the area has experienced sewage spills including a major spill (665,000 gallons)in March
2020 located at Harding and 72 Street (located 1500 feet east of the PVC).When the FIB at the PVC did not
decrease to below regulatory levels (following the March 2020 sewage spill)the CMB contracted to have
samples analyzed for Microbial Source Tracking (MST)markers between October 2020 and September 2021.
Results from these analyses indicated a dominance by dog markers with some evidence of human and bird
markers.As a result of these MST sampling efforts,the CMB developed an educational campaign to encourage
dog owners to properly dispose of dog waste.The CMB constructed facilities with doggie bags and garbage
bins with signage at the park area that leads to the PVC (Parkview Island Park)to encourage proper disposal of
dog waste and thus reduce contamination of runoff by dog fecal matter.
19
Additionally,the CMB has conducted a comprehensive set of studies of the area in attempts to isolate potential
sources of FIB.In addition to the efforts at reducing the impacts from dog waste,CMB has conducted extensive
studies evaluating the sanitary sewer system, inclusive of smoke testing,camera inspections,and acoustic
testing to identify potential leaks.For details see Montas et al.2023.For cases where leaks have been identified,
the City has taken corrective action.A repair was made to the sanitary sewer infrastructure during the first
weeks of February 2023 when twelve force main air release valves (from 77 Street just north of the PVC to
73'Street and Harding Court)were inspected and a subset of which (3)were found to be leaking.These air
release valves (at 75"and Dickens,74"and Dickens,and at 73"and Harding Court)were immediately replaced
at the time (between February 4 and February 12,2023).Regular inspections made since the replacements,as of
the writing of this report,indicate that the air release valves remain intact.
Concurrently,Miami Surfrider,a non-governmental organization which coordinates citizen's groups to engage
in water quality monitoring programs,initiated two sets of monitoring efforts.The first of which was initiated
October 2021 and consisted of weekly monitoring of PVC surface water at the Kayak Launch,at the same
location that the CMB conducts its monthly monitoring efforts.A comparison and analysis of the CMB and
Surfrider regular monitoring efforts are provided in Section II.I of this report.In addition to regular weekly
monitoring,Miami Surfrider organized two MST studies (JV 2022a,b) during July and August 2022 which
included PVC samples collected at the Kayak Launch location.Results from the Surfrider MST studies
indicated the presence of human marker within five of the six samples collected.
In addition to the work through CMB and Miami Surfrider,the University of Miami (UM)conducted an intense
targeted study during 2022.The 2022 study evaluated historical records of enterococci measurements and found
strong correlations with 24-hour antecedent rainfall and low canal-water salinity.Through measurements,the
study documented a large pulse of enterococci at the canal immediately after a storm event with the highest
levels found at the surface within a floating freshwater layer.The study also found highly elevated levels of
enterococci in the stormwater conveyance system with the highest levels towards the top of the water surface,
suggesting enterococci contamination of the shallow groundwater.These results collectively suggest that the
primary source of enterococci to the PVC was stormwater runoff which was contaminated by waste deposited
on surfaces that drain towards the PVC.Results from the 2022 study also found that between storm events,
enterococci levels were lower in the PVC but still elevated above the recreational guideline levels of 70 Most
Probable Number (MPN)per 100 mL.The enterococci levels between storm events coincided with tidal cycles
with higher levels observed during low tide.This pattern suggested that contaminated groundwater was also a
source of enterococci to the PVC.The source of contamination to the shallow groundwater was believed to be
either storm water runoff (from rainwater runoff from the streets)or leaking sanitary sewage.
The goal of this current study was to evaluate the ultimate source of shallow groundwater contamination.The
chapters and sections of the report that follow are intended to build upon the results from the UM 2022 study
by:1)analyzing regular monitoring data to include new data gathered between October 2022 and September
2024 (Chapter II),2)evaluating of the existing storm water conveyance infrastructure to understand when it
hydraulically connects shallow groundwater to the PVC (Chapter Ill),and 3)analysis of enterococci in
groundwater,stormwater,and surface water from the PVC (Chapter IV).Sample collection of these different
waters was augmented by MST (Chapter V)in efforts to determine the extent to which dog,humans,and
gulls/birds contribute towards these different water types.An overall assessment and recommendations are
provided in Chapter VI.
20
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Figure I.3:Location of Park View Canal within North Biscayne Bay and its interconnections through
secondary waterways to the bay.
21
Biscayne
Bay%aE
f$«ij i
Normandy Wate
Figure I.4:Map showing locations of I)Park View Canal,2)Biscayne Point Waterway,3)TatumWaterways,
4)Normandy Waterway N-S,and 5)Normandy Waterway E-W.
22
CHAPTER II
ANALYSIS OF HISTORICAL DATA
23
CHA PTER II
AN A LY SIS OF HISTORI CA L DA TA
The analysis described in this chapter is based upon the large amount of data collected and shared through the
CMB and through Miami Surfrider.The focus of this historical data analysis was to evaluate enterococci data to
document long term trends (Section II.l ),identify the sources of ambient data (Section II.2),and evaluate
correlations between enterococci and environmental factors (ambient plus water quality)(Section 11.3).
11.1 ANALYSIS OF HISTORICAL ENTEROCOCCI RECORDS OVER TIME
Two groups (CMB and Surfrider)have been regularly monitoring enterococci levels at the PVC.The CMB has
been monitored monthly for FIB since April 17,2019.Monitoring consists of collecting a water sample at the
Kayak Launch Pad within the PVC,followed by laboratory analysis to measure the Most probable Number of
enterococci per 100 mL (MPN/100 mL).In addition to monthly enterococci measurements,the CMB also
collects samples for another fecal bacteria,fecal coliform,plus for the analysis of nitrogen (nitrate +nitrite,
ammonia,and total Kjeldahl)and phosphorus (total).The results from sample analysis are augmented by field
measurements of basic physical-chemical parameters (water temperature,pH,salinity,specific conductance,
dissolved oxygen,and turbidity).
Miami Surfrider has been monitoring water quality at the same location as the CMB.Monitoring by Miami
Surfrider has been conducted weekly since October 14,2021.Their laboratory measurements are solely focused
on enterococci and are reported,like CMB,as MPN per 100 mL.The results from enterococci sample analysis
are augmented by field measurements of water temperature and with information about ambient conditions [air
temperature,wind speed and direction,and estimates of weather conditions (specifically qualitative descriptions
ofrecent rainfall and tidal height)].The Miami Surfrider data is available online at:
https://bwtf.surfrider.org/explore/57 /1183.
The first comparison between the data sets was to plot the two data sets in time series (Figure 11.1 ).Results of
this comparison emphasize the differences in the periods of record for each data set and the influence of the
different time frequencies of sample collection,with more samples collected by Surfrider during recent times.
Regardless of the differences associated with sample collection timing,both data sets emphasize that the
enterococci levels are chronically elevated exceeding the 70 MPN/100 mL threshold (red and yellow bars) most
of the time.When focusing on the green bars (below the 70 MPN/100 mL threshold),there appear to be fewer
green bars during the first half of the record (prior to 2022)compared to the second half of the record (2022 and
beyond),especially for the CMB data set.The color coding also includes a yellow bar for informational
purposes which corresponds to samples between 70 MPN/100 mL and the upper US EPA recommended limit
for kayaking in calm waters (370 MPN/100 mL).
Statistics were computed to further assess the historical records of enterococci over the period of record and
yearly (Section II.l.a),separated by antecedent rainfall (Section II.1.b)and separated by timing of mitigation
measures (Section II.1.c ).Statistical analysis of this data was conducted by first evaluating the distribution of
the data.The Shapiro-Wilk Test which is used to test for normality showed that the data was not normally
distributed so non-parametric statistical tests were chosen to further analyze the data.These non-parametric
tests include the Kruskal Test to evaluate multiple comparisons across data sets and the Mann Whitney U test to
evaluate individual pairs of data.Additionally,Chi-Square Tests were run to analyze categorical data (e.g.,
number of data points above or below the water quality threshold).This test was used to evaluate whether
24
frequencies (of above versus below a water quality threshold)were different among the different sets of
enterococei data evaluated.
C M B
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Figure II.I:Enterococci measurements at the PVC corresponding to the CMB dataset (top panel)and to the
Surfrider dataset (bottom panel).Green bars correspond to data points below the 70 MPN/100 mL
recommended recreational level for full body immersion,whereas yellow bars correspond to data points
between 70 and 3 70 MPN/l 00 rnL,conesponding to the recommended level for kayaking in calm waters.Red
bars correspond to data points which exceed the 370 MPN/I00 mL level.The ""over the red bars indicates
that the samples exceeded the 24.196 MPN/100 mL detection limit.The vertical lines separating the time series
corresponds to the 6-month period between August 3,2022,to February 3,2023,which is when the CMB
enhanced mitigation measures.Note the data are plotted on a logarithmic scale due to the wide range of
measurements.
II.1.a Period of Record and Yearly Evaluation of CMB and Surfrider Data Sets
We compiled sampling data corresponding to the period of record (POR)from April 2019 to September 2024
and found that enterococei levels for samples collected in the vicinity of the Kayak Launch pad continue to
regularly exceed the 70 MPN/100 mL threshold.The majority,especially for the CMB data set in more recent
years,fall within the 70 to 370 MPN/100 mL threshold for kayaking in cahn waters.Samples that exceeded the
detection limit of 24.196 MPN/I00 mL were observed only in the Surfrider data set in the last two years (Figure
II.I).As emphasized from the earlier UM study of 2022 and in the current 2024 study (described later).water
quality is much more variable with higher enterococci levels closer to the PVC water surface due to a
freshwater layer that floats atop of saltier water.Given this observation we expect higher and more variable
enterococei levels the shallower the water samples,which is reflected in the comparison of the CMB (sample at
a I-foot depth)and Surfrider (sample at 6-inch depth)data sets.
To further describe the exceedances at the PVC,enterococei levels for each year from the CMB and Surfrider
data sets were converted to exceedances above the 70 MPN/I00 mL beach advisory threshold,between the 70
and 370 MPN/l 00 mL kayaking recommended threshold,and to exceedances above the limit of detection of
24,196 MPN/I00 mL.For the CMB period of record,the 70 MPN/100 mL threshold was exceeded 85%of the
25
time,the 370 MPN/100 mL was exceeded 43%of the time,and the 24,196 MPN/100 mL threshold was
exceeded 3%of the time.For the Surfrider period ofrecord,the 70 MPN/100 mL threshold was exceeded 82%
of the time,the 370 MPN/100 mL was exceeded 44%of the time,and the 24,196 MPN/100 mL threshold was
exceeded 5%of the time.
Evaluating the historical data on a year-by-year basis showed that for the CMB data set (Table II.I,left hand
side),2019 was a year of particularly poor water quality with 11 %of the samples exceeding the 24,196
MPN/100 mL threshold and 89% of the samples exceeding the 70 MPN/100 mL threshold.For 2020 and 2021,
no exceedances of the 24,196 MPN/100 mL threshold were observed,although the lower threshold of 70
MPN/100 mL was exceeded 92%and 100%of the time during these years,respectively.In addition,the more
lenient threshold of 370 MPN/100 mL was also exceeded most of the time during 2020 and 2021.During 2022,
samples again exceeded the 24,196 MPN/100 mL threshold,and for this year it was measured for 8%of the
samples collected.The year 2023 appears to be a particularly good year (in comparison to other years)for water
quality.Samples collected during 2023 showed an improvement in water quality with none of the samples
exceeding the 24,196 MPN/100 mL threshold,9%exceeding the 370 MPN/100 mL threshold,and 45%of the
samples exceeding the 70 MPN/100 mL threshold.During 2024,all samples collected exceeded the 70
MPN/100 mL threshold,30%exceeded the 370 MPN/100 mL threshold,and none exceeded the 24,196
MPN/100 mL threshold.No apparent trend was observed with yearly total rainfall (note that 2019 and 2024 are
partial years),as 2020 was a particularly wet year (94 inches of rain measured at S27_R)with a median
enterococci level of 558 MPN/100 mL and 2021 was drier (60 inches)with a median of 1090 MPN/100 mL.
Evaluation of yearly rainfall totals in 2022 and 2023 against median enterococci levels further enforces the lack
of correlation with yearly rainfall totals,suggesting that long term rainfall trends are not a strong factor
impacting enterococci levels.Rather shorter term (e.g.,24-hour antecedent rainfall)plays a more significant
role in influencing the levels of enterococci in the PVC.
Evaluating the historical data yearly for the Surfrider data set (Table 11.1,right hand side)shows a relatively
consistent exceedance of the 70 MPN/100 mL threshold between 72%and 87%,and relatively consistent
exceedances of the 370 MPN/100 mL threshold between 31%and 54%.Exceedances of the 24,196 MPN/100
mL threshold varied between 0%and 8%per year with no distinct yearly trend.Associations with yearly
rainfall totals are limited for this data set due to the availability of only two full calendar years of rainfall data at
this time.Of note,for the two years of data available,the year (2023)with the higher rainfall total coincided
with a higher enterococci median value,in comparison to the year (2022)with the lower rainfall total and lower
enterococci median value.
When evaluating the means and medians of the CMB and Surfrider data sets the values were similar.No
statistical differences were observed between the median of the CMB data set and the median of the Surfrider
data set (p=0.89).On a year-by-year basis,the means and medians usually align within the same order of
magnitude suggesting a consistency between the data sets.These consistencies exist although two separate
groups collected samples using different sample collection methods.The CMB uses a certified laboratory for
sample analysis who collect samples using a pole sampler at a one-foot depth,whereas Surfrider enrolls citizen
scientists to collect samples using either a glass jar or a Whirlpak bag at a sample collection depth of 6 inches
below the water surface.Although Surfrider is not currently certified,the Surfrider sample collection process
includes documented protocols and training resources for citizen scientists to maintain consistency
(https://bwtf.surfrider.org/resources ).
11.1.b Separation of CMB and Surfrider Datasets Based Upon Antecedent Rainfall
To further evaluate the data,each set (CMB and Surfrider)were further split into two sets.The sets included
times with and without 24-hour antecedent rainfall (Table II.2).The split based upon antecedent rainfall was
chosen given that earlier analysis indicated that antecedent rainfall was the most significant environmental
26
factor influencing enterococci levels.For the CMB data set (Table II.2,top half of table),results from this
analysis show that percent exceedances were not sensitive to antecedent rainfall conditions.However,the mean
and median of the enterococci levels were sensitive.The median of the entire CMB data set was lower during
dry conditions (no 24-hour antecedent rainfall)compared to wet conditions (with 24-hour antecedent rainfall
(p=0.009).This statistical difference in the median was not observed when splitting the data by sample
collection year (p=0.48).Similarly,for the Surfrider data set (Table II.2,bottom half of table),the medians of
the enterococci levels were lower during dry conditions compared to wet conditions (p<0.001).Again,these
statistical differences were not observed when splitting the data by sample collection year (p=0.55).The
interpretation of this trend is that the baseline enterococci levels conditions,which are better represented by the
mean and median,are lower during dry conditions compared to wet conditions.The lack of statistical
significance when evaluating the data year-by-year may be due to the limited number of data points when
splitting the data into shorter one-year data sets.
Table ll.1:Means (arithmetic,geometric),median,and percent of exceedances of 70,370,and 24,196 MPN/100
mL thresholds per year for the entirety of the CMB and Surfrider data sets.The 70 is the guideline for
recreational bathing waters.The 3 70 is the recommended guideline for kayaking in calm waters.The 24,196
corresponds to the upper detection limit of the analysis method.Rainfall corresponds to station $27_R
CMBDataSet Surfrider Data Set
Total Arith.%%%Arith.Med}.Geo.%%%.Geo.Year Rain N Median ,,Exceed Exceed Exceed N Exceed Exceed Exceed
(inches)Mean ean 7 370 24,196 Mean ea!'Mean
70 370 24,196
2024°49.74 JO 727 295 408 100%30%0%38 3,175 373 504 87%50%3%
2023 77.49 11 137 52 65 45%9%0%50 2,548 427 372 72%54%8%
2022 70.00 12 2,362 245 327 83%42%8%52 2,301 243 335 81%31%4%
2021 60.23 11 2,905 1,090 1,039 100%73%0%10 484 227 184 80%40%0%
2020 93.71 12 3,200 558 602 92%58%0%NA"NA NA NA NA NA NA
2019 54.17 9 3,472 322 508 89%44%11%NA NA NA NA NA NA NA
Entire
Period of 405.34 65 2,113 297 370 85%43%3%150 2,484 324 370 82%44%5%
Record
"Data through September 30,2024
Data for CMB set starts April 17,2019
'Data for Surfrider set starts October 14,2021
'Not applicable.Prior to Surfrider monitoring period.
27
Table II.2:Means (arithmetic,geometric),median,and percent of exceedances of 70.370,and 24,196
MPN/I 00 ml thresholds per year including and excluding time periods with 24-hor antecedent rainfall.The
rainfall uses the WS3 weather station with S _27R as the backup.
Times with 24-hr.Antecedent Rainfall (wet)Times w/out 24-hr.Antecedent Rainfall (dry)
Arith.Geo.%o/o o/o Arith.Geo.o/o o/o o/o
Year N Median Exceed Exceed Exceed N Median Exceed Exceed ExceedMeanMean7037024,196 Mean Mean 70 370 24,196
CMB Data Set
2024°3 1.480 683 914 100%67%0%7 404 259 289 100%14%0%
2023 6 218 152 122 67%17%0%5 39 30 30 20%0%0%
2022 2 654 654 602 100%100%0%10 2.704 199 289 80%30%10%
2021 5 5.509 1.660 2.684 100%100%0%6 735 422 471 100%50%0%
2020 5 6.873 1.010 1.180 80%80%0%7 575 331 372 100%43%0%
2019%2 12.565 12.565 4.754 100%100%50%7 441 227 241 86%29%0%
Entire
Period of 23 4.091 683 804 86%70%5%42 2.136 292 367 84%29%2%
Record
Surf'rider Data Set
2024°15 6.081 2.359 1.906 93%80%7%23 1,280 185 212 83%30%0%
2023 23 5.120 677 1.035 91%70%17%27 356 160 156 63%41%0%
2022 22 3.973 538 751 95%55%5%30 1.075 194 185 77%13%3%
2021°1.019 1,019 1.019 100%100%0%9 425 218 152 78%33%0%
Entire
Period of 6l 4.876 905 1.071 93%67%10%89 844 185 178 74%28%1%
Record
Data through September 30,2024
"Data for CMB set starts April 17.2019
Data for Surfrider set starts October 14.2021
28
II.1.c Separation of CMB and Surfrider Datasets Based Upon Timing of Mitigation Measures
Data were separated into batches to evaluate whether improvements to water quality were observable during
key periods of mitigation.These batches were called "before","during",and "after"and corresponded to the
following time periods:
•Before:the time before August 3,2022
•During:the time between August 3, 2022,and February 3,2023,and
•After:The time after February 3, 2023,through September 30,2024
The time between August 3 and February 3 (6 months)corresponded to the period when the CMB transitioned
towards increased intensity of efforts to mitigate contamination to the PVC inclusive of increased frequency of
street sweeping, increased frequency of waste litter removal,additional community education and outreach to
encourage pet waste cleanup,outreach to homeless populations,reductions in feral animal feeding,enforcement
of trash bin covers,and replacement of the sanitary sewer air release valves.
For the CMB data set (Table 11.3,top third),comparing the enterococci measurements between each of these
periods shows an improvement in water quality between before and after periods."Before"had an arithmetic
average (2,700 MPN/100 mL),geometric mean (580 MPN/100 mL),and median (460 MPN/100 mL)higher
than "after"(430 MPN/100 mL,160 MPN/100 mL,and 220 MPN/100 mL for arithmetic mean,geometric
mean,and median,respectively).Percent exceedances of the 70 MPN/100 mL threshold dropped from 92%to
70%between before and after.Additionally,the percent exceedances of the 24,196 MPN 100 mL threshold were
reduced from 3%to 0%.Statistical analysis of the enterococci data separated between "before","during",and
"after"(using the Chi-Squared test),showed that statistical differences in the medians were observed only
between before and after (p=0.0 1 ),and no statistical differences were observed between before and during
(p=0.30) and between during and after (p=0.67).When evaluating the frequency of exceedances above the 70
MPN/100 mL threshold,the frequencies were not statistically different at 95%confidence limits but were
statistically different at 90%confidence limits (p=0.08).The most pronounced improvements were for the
frequency of exceedances above the 370 MPN/100 mL threshold.The frequency of exceedances above 370
MPN/100 mL threshold dropped significantly (p=0.02)from 56%during the "before"period to 20%during the
"after"period.
For the Surfrider data set (Table II.3),enterococci levels appear to be very similar or increasing from the
"before"to "after"period.The "before"arithmetic average (1,100 MPN/100 mL)was lower than the "after"
arithmetic average (3,000 MPN/100 mL).Similarly,the "before"geometric mean (220 MPN/100 mL)was
lower than the "after"geometric mean (430 MPN/100 mL).The same was observed for the median which was
lower "before"(220 MPN/100 mL)than "after"(400 MPN/100 mL).Statistical analysis of the enterococci from
the Surfrider data set showed no significant difference among the "before","during",or "after"groups
(p=0.128).When evaluating the frequency of exceedances above the 70 MPN/100 mL threshold,the
frequencies were not statistically different (p=0.29).For the frequency of exceedances above 370 MPN/100 mL,
the frequencies were again statistically different between before and after (p=0.05),but the results were
reversed with "after"showing a higher frequency of exceedance (51 %)compared to "before"(28%).
The results indicate that the CMB data sets show an improvement between "before"and "after"whereas the
Surfrider data are not as clear.The differences observed between the CMB and Surfrider data sets may be due
to the fact the CMB data set goes back further in time and therefore represents water quality when it appears to
have been poorer,whereas the Surfrider data set emphasizes more recent times.Also,when comparing the
coefficient of variation (Co Vs)between the CMB and Surfrider datasets,the CMB dataset has lower Co Vs (less
variability)which may also have influenced the ability to observe statistically significant differences within the
CMB and Surfrider data sets.The higher COY for the Surfrider set may be because samples are collected at a
29
shallower depth (6 inches)whereas the CMB samples are collected at a depth of one foot.As the next chapter
shows,the shallower the depth the higher the variability of the enterococci readings.This difference in sample
collection depth may also contribute towards the differences in documenting statistical differences between
"before"and "after".
When aggregating both data sets together (Table Il.3),no statistical differences were observed in the medians
between "before","during",and "after"(p=0.84).When evaluating the frequency of exceedances above the 70
MPN/100 mL threshold,the frequencies were not statistically different (p=0.13)for the different time periods
evaluated.
Table II.3:Statistics of CMB,Surfrider and Aggregated Data Sets Separated by Before,During and After
Enhanced CMB Mitigation Measures.Units for the average,geometric mean,median and standard deviation
correspond to MPN/100 mL.
%% %Arith.Geo.Coeff.N Exceed Exceed Exceed Median Std.Dev.
70 370 24,196 Average Mean Var(%)
CMB Data Set
Before 39 92%56%3%2,656 577 462 5,807 2.2
During 6 83%33%17%4,270 363 194 9,767 2.3
After 20 70%20%0%434 161 219 780 1.8
Surfrider Data Set
Before 40 80%28%3%1,094 221 222 3,846 3.5
During 27 93%48%4%3,081 505 350 7,307 2.4
After 83 80%51%6%2,959 427 404 6,485 2.2
Aggregated CMB and Surfrider Data Sets
Before 79 86%42%3%1,839 356 323 4,901 2.7
During 33 91%45%6%3,297 476 324 7,649 2.3
After 103 78%45%6%2,469 353 323 5,911 2.4
30
11.2 SOURCE OF AMBIENT DATA
Environmental factors,including ambient and water quality data,were compared to the historical enterococci
levels as measured by the CMB and Surfrider.Ambient data for comparison with the CMB and Surfrider data
sets included rainfall,tidal elevations,and groundwater elevations.Additionally,the 12-hour sampling effort
(described in Chapter IV) also required compilation of solar radiance.This section focuses on describing the
sources of ambient data.
The 2022 UM study (Montas et al.2023)provides a comprehensive assessment of local ambient environmental
monitoring stations.In the current 2024 study,a subset of the stations was utilized.Stations chosen were those
that were in closest proximity that provided reliable data with minimal data gaps.
Rainfall was compiled from two stations (Figure II.2,Table Il.4).These stations included one operated by the
CMB,station WS3,which was in operation during the time of this study and located within the catchment of
the study site (located at the North Shore Park &Youth Center).The other two CMB rainfall stations (WS 1 and
WS2)were not in operation at the time of this study due to construction activities on CMB properties.Data
from the closest station operated by the South Florida Water Management District (SFWMD)(S_27R),located
4 miles west of the catchment,was used to fill in the data gaps in the WS3 data set.
Tidal data were compiled from the National Oceanographic and Atmospheric Administration's (NOAA)Tides
and Currents repository (Virginia Key,Key Biscayne at Bear Cut).This site includes tidal predictions plus
confirmed tidal elevations every six minutes providing high resolution and reliability.The NOAA station at
Bear Cut in Virginia Key is the closest NOAA station with this level of resolution.The NOAA tidal data was
used to estimate the time of high and low tide at the PVC.The 2022 UM study established that the PVC
elevations (inclusive of high and low tides)were at a 17-minute time delay from the NOAA tidal station.
Groundwater monitoring data is available through the CMB.The closest station (Parkview Park,PVP)is
located within 100 feet of the southeastern bend of the PVC,located at the northeast corner of 72"Street and
Dickens Avenue within the parking lot of the North Shore Park and Youth Center (Figure II.2,Table Il.4).The
PVP groundwater monitoring station consists of three groundwater wells that are capped and protected from
surface contamination.These wells are screened at different elevations and include a shallow (screened at 25 to
35 feet),an intermediate (85 to 95 feet)and a deep well (200 to 210 feet).
Solar radiance data was available through Miami-Dade Weather Stem station located at Sunny Isles Beach
located 2.7 miles north of Haulover Cut.This station records wind speed and direction,air temperature and
solar data.
31
-80%12'-80°8'-80%4'
iv
Lu0Ln
(
Solar Radiance Station3Located2.7 miles north
«Baker's
Haulover Inlet
Miami
Mainland
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-80°12'-80°8'
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Rainfall Station*NOAA Tide Station
•Groundwater Station
Q Kayak Launch
3¥Solar Radiance
Figure II.2:Map showing locations of the rainfall.tidal.and groundwater stations relative to the Park View Canal (blue
line) and Kayak Launch.
32
Table II.4:Ambient Environmental Gauging Stations Providing Data Used for the Analysis of Enterococci Data
Ambient Station Agency Period 4r easure-GPS CoordinatesParameterNameResponsibleecordment URL for Station and/or Stations Description
Measured for Station Frequency N w
City of Miami Beach Station 3,located at the North
Rainfall WS3 CMB 12/13/13-30 25.85753 -80.12296 Shore Park &Youth Center (501 72nd St,Miami
Depth present minutes Beach,FL 33141 ).Data available through
Weatherlink.https://www.weatherlink.com/
SFWMD Rainfall Station S27.Located at spillway
on canal C-7.Located northwest of Biscayne
Boulevard and NE 83rd Street.
Rainfall 1/8/91-15 https://apps.sfwmd.gov/WAB/EnvironmentalMonitoDepthS27RSFWMDpresentminutes25.85123 -80.18837 ring/index.html(back up)https://my.sfwmd.gov/dbhydroplsql/show dbkey _inf
o.show dbkeys matched'?y station=S27 Ry js fl
ag=N
Virginia NOAA station 8723214 located at Bear Cut on pier
Tidal Key,NOAA 1 /28/94-6 minutes 25.7314 -80.1618 at UM Marine Campus.
Elevation Biscayne present https://tidesandcurrents.noaa.goy/stationhome.html?i
Bay d=87232l4
Groundwater Parkview 9/2/19-
Elevation Park CMB present(PVP)
FSWN Miami-
Solar Sunny Dade 3/29/22-
Radiance Isles Weather present
Beach STEM
hourly 25.85724 -80.12490
Three values provided at this station.Elevations are
provided for a shallow well screened at 25 to 35 feet,
intermediate well at 85 to 95 feet,and deep well at
200 to 210 feet.Data available through Hydro Vu.
https://www.hydrovu.com/t/download/graph-
export/5954062857404416
FSWN Sunny Isles Beach station.Includes wind,
minute 25.93743 -80.12036 temperature,and solar data.
https://miamidade.weatherstem.com/fswnsunnyisles
11.3 RELATIONSHIPS BETWEEN HISTORIC ENTEROCOCCI LEVELS AND
ENVIRONMENTAL FACTORS
The available enterococci data were compared with environmental factors (consisting of both ambient and water
quality data)to evaluate potential associations that can be used to explain the enterococci levels.As mentioned
in Section Il.1,two sources of historic enterococci data were available,those from the CMB and those from
Miami Surfrider.A summary of the available environmental factors available for each set of data are provided
in Table IJ.5.The comparison shows that the CMB data set is much more comprehensive in terms of the water
quality parameters measured.Although the period of record is longer for the CMB data set (5.5 years starting
April 2019),the frequency of sampling is monthly providing for a total of 65 sampling days,which is fewer
sampling dates than the Surfrider data set.As a result of the weekly sample collection frequency,the Surfrider
data set consists of more sampling days (150 days),even though sampling by Surfrider started later (3 years
starting October 2024).Water temperatures were available for both the CMB and Surfrider datasets.
33
Additionally,because sample collection day and time were available for both data sets,we were able to
associate the enterococci data with ambient data including antecedent rainfall (6-hour,24-hour,and 48-hours as
measured at WS3),groundwater elevations at Parkview Park (for the shallow,intermediate,and deep wells),
tidal elevations (measured at the NOAA station and estimated for the PVC),and differences between elevations
to evaluate direction of flow between the PVC and groundwater.
For the CMB data set,the more comprehensive measurements included nutrients including three forms of
nitrogen (nitrate+nitrite,ammonia,and total Kjeldahl nitrogen)plus phosphorus (total).During sample
collection,field measurements for the CMB data set also included additional physicochemical parameters
(salinity,specific conductance,pH,water temperature,dissolved oxygen,and turbidity).Since salinity and
specific conductance are linearly correlated,additional analysis focused on using salinity only.Details about the
rainfall and tidal stations are available in Section II.2.The enterococci and ambient and water quality data
utilized for analysis are provided in Appendix A.
The following subsections provide summary statistics for the ambient and water quality data for the CMB data
set (Section II.3.a)and evaluate correlations between enterococci and environmental conditions for the CMB
data set (Section II.3.b).
Table II.5:Comparison of data available through the CMB and Miami Surfrider data sets.
Period of Record
Sampling Frequency
Number of Sampling Days
Water Quality Data
CMB
Apr.17,2019,to Sept.30,2024
Monthly
65
Enterococci
Water Temperature
Fecal Coliform
Nitrate+Nitrite
Ammonia
Total Kjeldahl Nitrogen
Total Phosphorus
pH
Salinity
Specific Conductance
Dissolve Oxygen
Turbidity
Miami Surfrider
Oct.14,2021,to Sept.30,2024
Weekly
150
Enterococci
Water Temperature
Ambient Data.Used for
the analysis of both data
sets.
6-hour Antecedent Rainfall
12-hour Antecedent Rainfall
24-hour Antecedent Rainfall
48-hour Antecedent Rainfall
Groundwater Elevation,Shallow Well at PVP
Groundwater Elevation,Intermediate Well at PVP
Groundwater Elevation,Deep Well at PVP
Tide Elevation at NOAA Station
Estimated Water Surface Elevation at the PVC
Difference between PVC Water Surface Elevation and Groundwater Elevation
34
11.3.a Average Environmental Conditions During Sampling for the CMB Data Set
Average environmental conditions of the PVC during CMB sampling are within expected levels for
predominantly marine waters.The arithmetic averages of the measurements included:water temperature (26.8
C),salinity (29.4 psu),pH (7.93),turbidity (5.0 ntu),dissolved oxygen (5.2 mg/L),nitrogen (0.055 mg/L as
ammonia,0.049 as nitrate +nitrite,0.32 mg/L as TKN),and total phosphorus (0.023 mg/L)(Table II.6).A few
of these environmental conditions are listed within the FDEP Florida Surface Quality Criteria (FAC 62-304.530,
2016 and FAC 62-302.400,2013 for dissolved oxygen (see floridadep.gov/dear/water-quality-
standards/content/surface-water-quality-standards-classes-uses-criteria).The parameters that are within the
criteria (for a Class III and Class III-Limited water in predominantly marine environments)included pH (between
5 and 9 .5),dissolved oxygen (4.0 mg/L for 56%of saturation),turbidity (<29 ntu),and ammonia (<0.49 mg/L as
computed using the average temperature and pH).General FDEP water quality criteria include references to
nutrient levels (F AC 62-302.300),suggesting that good quality waters are characterized by total nitrogen (e.g.,
TKN)of less than 0.3 mg/L and total phosphorus of less than 0.04 mg/L.However,specifically for Class III
marine waters,the criterion for total phosphorus is listed as <0.001 mg/L (FAC 62-304.530).Since the PVC is
influenced by freshwater inputs,we interpret that the nutrient levels (nitrogen and phosphorus)are within or near
acceptable levels.The only criterion that is clearly not met by the FDEP Class Ill criteria are the enterococci with
a measured geometric mean of 3 70 MPN/100 mL in the PVC for the CMB data set.This value is higher than the
Class III regulatory guideline geometric mean of :S35 MPN/100 mL.
To assess environmental conditions when the enterococci levels were within regulatory limits,the CMB data set
was split into a set corresponding to values when enterococci was below the 70 MPN/100 mL threshold and
another set corresponding to values when enterococci was above.Results from Mann Whitney U Tests show that
samples with enterococci levels below 70 MPN/100 mL,had:
•Higher salinity (p=0.30)
•Higher pH (p=0.07)
• Higher turbidity (p=0.46)
•Higher dissolved oxygen (p=0.29)
•Lower antecedent rainfall (p=0.35)
•Higher tides (p=0.29)
•Lower groundwater elevations (p=0.37)
These characteristics suggest that low enterococci levels were dominated by oxygenated and turbid marine waters
of higher pH during times with minimal antecedent rain,during periods of high tide (further enhancing tidal
influence),and lower groundwater elevations (with lower contributions from groundwater).Times with
enterococci above 70 MPN/100 mL were characterized by fresher waters of lower pH,lower turbidity,and lower
dissolved oxygen.These fresher waters were observed after rainfall conditions,when the tides were lower,and
when the groundwater elevations were higher.Statistically,the parameter that was significantly associated with
the 70 MPN/100 mL exceedance was pH;however,the dominance of antecedent rainfall (and secondarily salinity)
in their associations with levels of enterococci should also be considered heavily (See next section).
35
Table II.6:Average of water quality measurements for the available period of record fromCMB.Each data set
was further split into samples with enterococei levels below the 70 MPN/I00ml threshold (green)and levels
above the 70 MPN/I00ml threshold (red)
For samples where For samples where
Entire Data Set enterococei were less than enterococci were greater
70 MPN/100 ml than 70 MPN/I00mil
Parameter Number of Arithmetic Number of Arithmetic Number of Arithmetic
Data Points mean Data Points Mean Data Points Mean
Enterococci (MPN/100 m.L)65 2.113°10 33 55 2.498
Fecal Coliform (MPNI00 mL)62 266%10 79 52 303
Water Temperature (C)64 26.8 10 26.9 54 26.9
Salinity (psu)64 29.4 9 31.6 55 29.0
pH 65 7.93 10 8.20 55 7.88
Turbidity (ntu)64 4.96 9 7.25 55 4.68
Dissolved Oxygen (mg/L)65 5.22 10 5.85 55 5.11
Nitrogen,Ammonia (mgL)51 0.055 6 0.056 45 0.059
Nitrogen,Nitrate +Nitrite 54 0.049 7 0.033 47 0.047(mg/L)
Nitrogen.Kjeldahl (mg/L)58 0.32 10 0.32 48 0.32
Total Phosphorus_(mg_I)61 0.023 10 0.015 51 0.024
6-hr Rainfall (inches)65 0.02 10 0.00 55 0.02
12-hr Rainfall (inches)65 0.11 10 0.00 55 0.13
24-hr Rainfall (inches)65 0.26 10 0.01 55 0.31
48-hr Rainfall (inches)65 0.48 10 0.03 55 0.56
Tide at PVC 65 -0.72 10 -0.52 55 -0.75(ft:NA VD88)
Tide at NOAA Station 65 -0.35 10 -0.13 55 -0.39(ft;NAVD88)
Shallow Groundwater 24 0.09 2 -0.37 22 0.14Elevation(ft:NAVD88)
Intermediate Groundwater 37 -0.09 4 -0.16 33 -0.08Elevation(ft:NA VD88)
Deep Groundwater 35 2.67 4 2.38 31 2.7Elevation(ft:NA VD88)
Enterococei geometric mean and median for the entire CMB data set was 370 MPN100 mL and 297 MPNI00 mL.respectively.
"Fecal coliform geometrie mean and median for the entire CMB data set was 140 MPN100 mL and 142 MPN/100 mL.respectively.
Fecal coliform standard not currently applicable to Class III and Class III-Limited waters.Applicable currently to shellfish
harvesting waters (Class ID) with median values not to exceed I4 MPN/100 mL for shellfish harvesting.Fecal coliform standard
applied to Class III waters prior to the end of 2016.At this prior time,the monthly average was to be _200 per 100 mL for Class III
II.3.b Evaluation of the CMB Data Set for Correlations with Environmental Conditions
To evaluate changes between enterococci concentrations and the environmental factors,exploratory data
analysis was conducted by computing Pearson's correlations and Spearman's ranked correlations for the CMB
data set.Details of the correlations analysis can be observed in Figures II.3 through II.6,where all correlations.
both Pearson and Spearman are plotted and shown.A summary of the correlations for enterococci is given in
Table II.7.Correlations were considered significant at 95%confidence limits for p-values less than 0.05.
Statistically significant Spearman correlations (hr,/0.28,p-0.05)were found between enterococei levels and
salinity,fecal coliform,pH,and total phosphorus,plus 12-hour,24-hour,and 48-hour antecedent rainfall.The
36
strongest relationships were observed with fecal coliform (rs =0.55)and for 24-hour antecedent rainfall (rs=
0.41).Results for Pearson's correlation showed that statistically significant correlations (IRl>0.26,p<0.05)were
found between enterococci levels and salinity,fecal coliforms,and 6-hour,12-hour,24-hour,and 48-hour
antecedent rainfall.The strongest relationship was observed for 24-hour antecedent rainfall (R=0.64).It is
interesting to note that a negative relationship was observed between enterococci and salinity.That is the higher
the salinity,the lower the concentration of enterococci.Conversely,the lower the salinity (or higher freshwater
content),the higher the concentration of enterococci.
Results from multiple linear regression further confirmed that rainfall,in particular 24-hour antecedent rainfall,
was the primary parameter correlated with enterococci.Although the model was set up to evaluate multiple
parameters,24-hour rainfall was by far the parameter that contributed the most towards explaining the
variability of the enterococci levels.The model developed (Equation II.l)relates P (24-hour antecedent rainfall)
to enterococci levels in units of MPN/100 mL as follows:
Enterococci (MPN/100 mL)=1102 +3732 x P
37
(Equation II.1)
Table II.7:Correlation between the enterococci in samples collected monthly from Miami Beach (4/17/2019 -09/30/2024)with other physical
chemical parameters (water level.tide cycle.total nitrogen.total phosphorus,salinity.fecal coliforms.field specific conductance,field temperature,
pH,dissolved oxygen,turbidity and cumulative precipitation [6-hour,12-hour,24-hour.48-hour])based on both Pearson's and Spearman's analysis.
Yellowy_indicates significant_correlation(c"""indicates aalue<0.05.·"indicates a value<0.01
l tool saw c.,,n«ea s ow -nu_psst«d n o»wan«6e r
Kjelda»Phosphorus (ppt)(CF/Io Conductance Temp.Field pH Oxygen Tt»'Ra infalldzmag)%"r nuhoscm)co c g1)@s)
12-hour
Ra infall
(in)
24-hour
Rainfall
(in)
48-hour
Rainfall
(in)
Water
Level
(N OAA,ft)
Pearson Correlation
Correlation:Coefficient 0.0440 0.2213 -0.3985 0.2597 -0.0519 -0.0652 -0.0955 -0.0104 0.0621 0.3661 0.5770 0.6371 0.4788%0.0377
Enterococci (R)
(MIPN100
mL)p-value 0.7405 0.0813 0.0011 0.0415 0.6815 0.6086 0.4492 0.9345 0.6259 0.0027 <0.001 <0.001 <0.001 0.7655
--
Spearm an Correlation
corr elation:Coefficient 0.0178 0.3173 -0.3760 0.5496 -0.0890 0.0312 -0.2915 -0.0886 -0.0089 0.2218 0.3360 0.4084 0.3744 -0.0595
Enterococci (Rs)
(MIPN/100
mL)p-value 0.8931 0.0113 0.0022 <0.001 0.4806 0.8064 0.0185 0.4828 0.9445 0.0758 0.0062 <0.001 0.0021 0.6377
Sample size 58 61 64 62 65 64 65 65 64 65 65 65 65 65
38
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Figure II.3:Correlation plot (Pearson) between enterococci and environmental faetors for the CMB data set.
Green shading indicates correlations that were statistically significant.
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Figure II.4:Correlation plot (Spearman)between enterococci and environmental factors for the CMB data set.
Green shading indicates correlations that were statistically significant.
39
-1.5 0.0 1.0 -1.0 0.0 1.0 1.5 2.5 3.5 -1.$0.0 1.0
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Figure II.5:Correlation plot (Pearson)between enterococci and water elevation data for the CMB data set.Green
shading indicates correlations that were statistically significant.
-1.5 0.0 10
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Figure II.6:Correlation plot (Spearman)between enterococci and water elevation data for the CMB data set.
Green shading indicates correlations that were statistically significant.
40
CHAPTER III
ANALYSIS OF THE
STORMWATER CONVEYANCE SYSTEM
41
CHAPTER III
AN A LY SIS OF THE ST OR M W A TER CONVEYANCE SYSTEM
The analysis of the stormwater conveyance infrastructure focused on analyzing the conditions during which it
would be inundated with water.These conditions included being inundated by water from the PVC,specifically
during high tide,and being inundated by groundwater.Direct measurements of groundwater were available
through the CMB as described in prior Section II.2 with summary data in Table 11.6.However,there were no
direct measurements of water level in the PVC.Due to the lack of measurements,a relationship was developed
between the tidal height at the PVC and the tidal height as documented by the NOAA tidal station located at
Virginia Key at Bear Cut (Section 111.1).Once the water elevations were estimated,they were superimposed on
an image of the storm water conveyance system showing the extent to which it is inundated during different tidal
and groundwater conditions (Section III.2).
111.1 ESTIMATES OF PVC WATER SURFACE ELEVATIONS
To establish a relationship between water surface elevation at the NOAA tidal station and the PVC,a benchmark
was needed.This benchmark was installed by M.G.Vera and Associates (Mark Sowers)in collaboration with
TYLin (Jeffry Marcus)during the week of August 5,2024.The benchmark is located on a piling (southwest
corner)of the Kayak Launch (Figure 111.1).The elevation of the benchmark is 3.00 feet referenced to the National
American Vertical Datum of 1988 (NA VD88).This benchmark has since been used to measure the elevation of
the PVC water surface by measuring the vertical distance from the benchmark to the water's surface.
Measurements of PVC water surface elevation were taken hourly from 6:00 am to 5:00 pm on August 15,2024.
Additional spot checks were made on August 6,2024,at 11 :00 am,1 :00 pm and 3:15 pm and on September 19,
2024,at 2:45 pm and at 4:07 pm.
Figure III.1:Benchmark established at the Kayak Launch of the PVC showing the elevation as 3.00 feet
NAVD88.Benchmark and photos courtesy of M.G.Vera and Associates and TYLin.
42
During the hourly surface elevation measurements on August I5, 2024,low tide at the PVC occurred between the
12:00 noon and 1:00 pmmeasurement period.To interpolate for the exact timing of low tide,a fifth order
polynomial was fit to the tidal curve.The extreme low tide at the PVC was estimated to be at 12:20 pm.This was
compared to the time of extreme low tide at the NOAA station (12 06 pm).Results of this comparison showed
that the timing of the PVC low tide was offset from the NOAA station by I4 minutes (low tide at the PVC is 14
minutes after low tide at the NOAA station).The analysis conducted during the 2022 study found that the offset
was 17 minutes.For consistency with the 2022 study the offset of 17 minutes was used again.
Once the data were adjusted for the timing offset, the elevation of the PVC was plotted in time series against the
elevation of the NOAA tidal station (Figure III.2).From this plot,an offset in elevation was observed where the
measured elevation at the PVC during low tide was lower than the measured elevation at NOAA during low tide
(Figure III.2).After testing a few models,the data were fit using four relationships as follows (Table III.1):
7:12 9M
0.4
12:00AM 4:48 AM 9.36 AM 2:24 PM 712PM 12:00 AM
NOAA Measurements O PVC Measurements a M odeled for PVC
-0.1
C0z 0.6>dLI
a....,
(I)
Ee....,
0
LLI
-1.6 -
Po
f '1 +a•o¢i%40Og°
971,I \l~
#?
0 000aaO□\□4
1.1 -6D
Time (12am -12pm ,Auu st 15,2024)
Figure III.2.Elevation at the NOAA Station at Bear Cut on Virginia Key versus Measured and Modeled Elevation
at the PVC.
43
Table III.l:Model developed to estimate PVC water elevation from measured elevations at the NOAA station on
Bear Cut at Virginia Key.
Tide Condition Illustration Type of Curve Equation"
high tide to one hour "\1beforelowtide Sine y=0.9 sin(1.5x+1.4)-I
.toot
one hour before low tide t4 ii
to low tide 'Polynomial y =-0.5561+0.0635x 0.112
M.•low tide to one hour t ii
after low tide 4 Polynomial y=0.439+2.0209x +0.2483l
one hour after low tide /Itohightide Sine y=0.9 sin(1.67+1.7)-1 .06
aa et
In these equations.is the tidal elevation at NOAA at time t minusl7 minutes and y is the modeled elevation at the PVC at time t.
To check the accuracy of the elevation model for PVC water surface elevation,the results of the model were
checked against water elevations measured on August 6 and September I9.Results show the model has variable
performance against the independent data points.The accuracy of the PVC elevation estimate varies between 0.08
and 0.60 feet.Future work is recommended to develop a better model,one based upon minute-by-minute water
level elevations at the PVC using an automated water level data logger over the course of several months.The
availability of a larger data set for calibration and verification would allow for the development of a more robust
model.
Using the model described in Table III.l,PVC water surface elevations were estimated for the CMB data set and
for the Surfrider data set (Table III.3).Data analysis indicates that the mean elevation of the PVC was -0.73 feet
NGVD88 with a maximum of -0.10 feet and a minimum of-1.95 feet.
To complete the analysis,mean groundwater elevations were also computed.The mean groundwater elevation for
the shallow well was -0.05 feet with a maximum of 2.40 feet and a minimum of -1.23 feet.These elevations were
used in the next section to assess the inundation of the stormwater system.
44
Table Ill.2:Results from applying the model to estimate PVC water surface elevations using an
independent set of water level measurements
Elevation EBB or ModeledMeasuredat the DifferenceDateTimePVCFLOODatElevation(ft)
(ftNAVD88)NOAA (ft NAVD88)
11:00AM 0.33 FLOOD -0.19 0.53
Aug.6,2024 1:00 PM 0.00 EBB -0.10 0.10
3:15 PM -1.00 EBB -1.08 0.08
2:45 PM 0.33 EBB -0.27 0.60
Sep.19,2024
4:07 PM -0.38 EBB -0.32 -0.05
Table III.3:Descriptive statistics of PVC water surface,NOAA station water surface,and
groundwater elevations at the Parkview Park monitoring stations.All elevations in feet,
NGVD88
Station Arithmetic Min.10%25%75%90%Max.Mean
PVC -0.73 -1.95 -1.51 -1.09 -0.27 -0.16 -0.10
NOAA Tidal -0.29 -1.85 -1.33 -0.96 0.35 0.79 1.79Station
Groundwater,-0.05 -1.23 -0.99 -0.6l 0.25 0.79 2.40ShallowWell
Groundwater,-0.30 -1.6l -1.08 -0.75 0.09 0.43 1.53IntermediateWell
Groundwater,Deep 2.76 1.49 1.92 2.40 3.14 3.47 4.20Well
45
III.2 IN UN DATION OF TH E STOR M W ATER CONVEYANCE SYSTEM
Inundation corresponds to areas of the stormwater conveyance system where the inverts of the stormwater pipes
are below the groundwater or PVC tidal elevations.If the stormwater pipe invert elevation is below the
groundwater,it can potentially skim the upper layers of the groundwater towards the PVC when the hydraulic
gradients are in favor of flow towards the PVC.Similarly,if the stommwater pipe invert elevation is below the
PVC water level,it can carry water from the PVC back into the groundwater system when hydraulic gradients
favor flow towards the landside or interior of the stormwater conveyance system.In other words,depending upon
the elevation of the stormwater conveyance system,inverts relative to groundwater and PVC tidal levels,water
will move back and forth through the stormwater conveyance system resulting in an exchange between PVC
water and groundwater.
The area contributing stormwater to the PVC (81.3 acres or 329,000 m)extends from 76"Street including most
of the Biscayne Beach Elementary School property on the north.72 Street to the south,the entirety of Parkview
Island to the west,and Collins Avenue to the east (Figure III.3).The analysis of the pipe inverts of the stormwater
conveyance systembegan with an analysis of information available from the City of Miami Beach Geographic
Information System (GIS).The GIS data was then augmented with elevations available through construction
drawings of the stormwater conveyance system (Details in Appendix B).For sites with no elevation data by GIS
nor construction drawings,the CMB surveyed the invert elevations of the pipe outlets that lead to the PVC.A
summary of the pipe invert elevations (Figure III.4)shows that the inverts of pipes contributing directly to the
PVC vary from +1.0 to -4.6 feet NGVD88.
g ?----,3 ;,»,»h a,ta,?••Iedsalsa±bdliula I
earth for»
-,I }I
I
I
I
t
I
I
I
I
I
I
llFi'Ee-x s}
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.yh s h eP··t:."\
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t
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i-..ir....·-,~,~.--~-~=='-=--.--~------~,.;;:.-r.11.~""'---h~ilil'-~~---..1\~f--~lll!,,....r.lil---l~-,l ~"'
i ±2
t
J
Figure III.3:Stonnwater conveyance system contributing to the PVC.The PVC is shown with a dark blue line.
The stormwater catchment area is shown in dashed reel line.Stormwater conveyance system in green from Miami
Beach Geographic Information System along with hand drawing of storwater infrastructure at the Biscayne
Beach Elementary School in black.
46
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Figure IIl.4:Storm conveyance system emphasizing elevations (feet NGVD88)of pipe inverts.
47
The information documenting pipe inverts of the stormwater conveyance systemwas combined with average
elevations of the groundwater (shallow well)at the PVP station and the tide at the NOAA station.This was clone
to determine areas of stormwater conveyance system inundated during periods of varying from 10% t0 90%of the
groundwater elevations (Figure III.5)and of the tidal elevations (Figure III.6).The elevation of the tide at the
NOAA station was chosen over the modeled tide at the PVC due to the need to establish a more robust model for
the tide at the PVC.The result of this analysis shows that most of the stormwater conveyance system is inundated
by groundwater and from the tides.The easter limits of the conveyance system impacted by inundations extends
farther east during periods of high groundwater and during periods of high tide.
2£
tao#tart»
I
J
r Groundwater 90%0.79
t Groundwater 10%-0.99
Figure III.5:Stormwater conveyance system with areas of groundwater inundation shown during the lowest 10%
elevation (-0.99 ft NGVD)and the highest 90%elevation (0.79 ft NGVD).
m Tidal Height 90 percent 0.79
Tidal Height 10 percent -1.33
Figure III.6:Stonmvater conveyance system with areas of tidal inundation shown during the lowest I 0%
elevation (-1.33 ft NGVD)and the highest 90%elevation (0.79 ft NGVD).The reference for the tidal data is the
NOAA station located on Virginia Key at Bear Cut.
48
111.3 SANITARY SEWER SYSTEM
In addition to the stormwater conveyance system,another source of fresh water within the watershed is sanitary
sewage.The eastern portion of the watershed,the portion corresponding to the main island of Miami Beach,
serves as a transmission pathway of sanitary sewerage from northern areas of Miami Beach and Miami Dade
County.The area includes a 16-inch force main that runs along the northern leg of the PVC,and a pump station at
the end of 75"Street near Dickens Avenue.From the pump station,the force main continues (24 inch)along
Dickens Avenue,and heads cast along 73"Street.Another 36-inch force main runs between Harding and Collins
Avenue with an intricate series of cross connections below the parking lot located between 72"and 73"Street
and Harding and Collins A venues.This intricate network is near the historic ocean outfall (36 inch)that is no
longer in service that runs east along 74""Street towards the ocean.
In addition to the force mains along the eastern side of the watershed,all the residential and commercial buildings
are serviced by gravity sewer mains.The sanitary sewage from all buildings within Parkview Island flow by
gravity (6-to-8-inch lines)towards the northeast side of the island with a siphon crossing below the depths of the
PVC toward 75""Street.On the east side of the watershed on the Miami Beach main island,the gravity sewer
lines (6-to-8-inch lines)predominantly run north south except for a gravity main (12-to-18-inch lines)which run
east west along 75"Street.
Citywide assessment and rehabilitation of sanitary sewer was prioritized in the Parkview Island area and North
Beach because of the water quality issues.The public portion of the gravity systems have been inspected and both
gravity pipes and manholes have been lined to stop exfiltration to groundwater starting 2023 and completed by
late 2024.Laterals in the public portion have been inspected and were found in good condition while the laterals
on private property upstream of the public system have not been inspected due to the City's lack of authority on
private property.Aged and outdated lateral materials on private property can present a source ofleakage to
groundwater.Sewer Pump Station no.23 wet well located at 75"Street and Dickens was rehabilitated to stop
exfiltration November 2024.It is recognized that the force mains are aged with susceptibility to leakage.The
potential for leakage is continuously monitored by the City of Miami Beach through an existing system
(Supervisory Control and Data Acquisition,SCADA)that documents for pressure differentials.Also,the CMB
(through a consultant,Utilities Services Associates)recently completed (as of September 20,2024)a more
sensitive analysis based upon acoustics and sonar.This study showed no leaks in the sanitary sewer force main
system.An image of the sanitary sewer system super-imposed on the storm water conveyance system shows many
overlaps (Figure 111.7).However,no leaks have been detected so far within CMB property.
Figure 111.7:Stormwater conveyance and sanitary sewer system overlay showing crossings between the
stormwater and sanitary sewer.This image was retracted due to the inclusion of sewer system details which is
restricted for distribution.
49
CHAPTER IV
ANALYSIS OF ENTEROCOCCI IN GROUNDWATER,
STORMWATER,AND WITHIN THE PVC CANAL
50
CHAPTER IV
ANALYSIS OF ENTEROCOCCI IN GROUNDW ATER,
STORMWATER,AND WITHIN THE PVC CANAL
Sampling efforts included:1)groundwater sampling (Section IV.1),2)stormwater sampling (Section IV.2),and
3)sampling within the PVC Canal (Section IV.3).Combined results are provided in Section IV.4.Sampling
within the PVC included intense temporal and depth sampling at the Kayak Launch and sample collection at the
stormwater outlet of the BBE.Section IV.5 puts the results from the stormwater and PVC samples in the context
of the literature.
The time line for sample collection efforts superimposed on the rainfall record is illustrated below (Figure IV.I).
Groundwater sampling and first day of runoff sampling (last half of July)corresponded to a relatively dry period.
Day 2 through Day 7 stormwater sampling efforts corresponded to variable size storms.The hourly sampling at
the Kayak launch was preceded by a six-day dry period with rainfall occurring at the very end of the sampling
event.BBE canal samples were collected interspersed throughout the sampling period.
8
7
2 08/05/24
BE -Canal
Sampling
08/06/24
Stormwater
Sampling Day 2
08/09/24
Stormwater
Sampling Day 3
08/15/24
12hr Kayak
Launch Sampling
08/20/24
BE -Canal
Sampling
08/20/24
Stormwater
Sampling Day 4
08/23/24
Stormwater
Sampling Day 5
08/23/24
BBE -Canal
08/29/24
Stormwater
Sampling Day 6
08/29/24
BBE -Canal
Sampling
■WS3_DAILY _SUM
S27_R_DAILY_SUM
09/10/24
Stormwater
Sampling Day 7
09/19/24
BBE -Canal
Sampling
6-u
a0.c:07/23/24 -07/25/24O5GroundwaterrSampling-.....-0 4 07/25/24-C:Stormwater
cu Sampling Day 1
cc 3>cuo
1
0 t t t t t t t t t t t ¢t <t t <t t t t tNyyNyyyyyyyyyNyyyyyyooo o o o o o o o o o o o o o o o o oNjy~y v y y e y N j e e e y ~e y y;:;;R Gs ....;;;;:;;R G ....;;i G 2 O o y G DO co >;;i...........y ~y y g )5 a 3 ... ... ...e ....y eRRR:R R R R co s s o s o 00
I I ~
t t t t t t t t t t t t <t t 3 tyyyyy y y y y y y y y y No o o o o o o o o o o o o o o oyyNyyyy~y N ~y y y y NGui>>;:;;;;a a;Gs ;:;9 a R Gs ;:;;;;y y N M G Gs Gs a e4 ......l 4 4 es s G o Gs Gs G Gs .....Gs0 0
Figure IV.I:Sample collection timeline superimposed on daily rainfall record.Bars correspond to daily rainfall totals with
the dark blue bar corresponding to the City of Miami Beach rain gauging station (WS3)and the orange bar corresponding to
the South Florida Water Management District rain gauging station (S27_R).
For this study,all samples were collected in either sterilized polypropylene bottles or pre-sterilized Whirlpak
bags.One liter of water was collected per site.Upon collection,water temperature was taken using a hand-held
laser thermometer (MT Raytek®).Samples were returned immediately to the laboratory for processing the same
day.A detailed listing of which samples were collected which day is provided in Table C.1 in Appendix C.Upon
receipt at the laboratory samples were split three ways (Figure IV.2).
51
•One split (either 10 mL or 1 mL)was used for enterococci analysis.All enterococci analyses were
performed using chromogenie substrates (Enterolert.IDEXX Industries). a standardized well system
(Quantitray-2000),and incubation temperatures consistent with enterococei measurements (41.5 C for 24
hours ±2 hours).Trays were checked for fluorescence at two time points (24 hours and at 26 hours for
confirmation of lightly fluorescing wells).Results from these analyses are provided in units of Most
Probable Number (MPN).The chromogenie substrate and Quantitray approach were chosen because it
provides the broadest range of detection (from l to 2419.6 counts)for a single analysis,thereby increasing
the chances of direct measurements of enterococei concentrations.In addition,it is the same approach
used for the CMB and Surfrider data sets.In this study,dilutions of 10:1 were preferentially used early
during the study thereby providing analytical ranges betw een I0 and 24,196 MPN per 100 mL .However,
starting on August 20,2024.the dilutions were changed to 100:1 given that the stormwater samples
consistently showed values above 24,196 MPN per 100 mL.At a dilution of l 00:1,the range of
quantification corresponded to <100 to 241.960 MPN/100 mL.
•The second split was utilized to prepare an "MST"filter (Pall GN-6.,47 mm diameter,0.45 pm pore
size).A subset of these filters (n=78)was then chosen for MST analyses.These filters were processed
aseptically by vacuum filtration using sterilized re-usable magnetic filter holders.Sample filtration
volumes varied from clogging (80 mL minimum)up to a maximumof 500 mL.Once the samples were
filtered, the filters were folded 4 times and placed into pre-labeled presterilized 5 mL centrifuge tubes
(Eppendorf)containing 1.5 mL of lysis buffer to preserve the sample (DNA/RNA Shield,Zyrno Research
Corp.).The filters were then placed in a -80 C freezer until delivery to the laboratory that processed the
samples for MST (National Oceanic and Atmospheric Association Atlantic Oceanographic and
Meteorological Laboratory,NOAA -AOML.led by Drs.Christopher Sinigalliano and Maribeth Gidley).
•The third split was processed for basic physical-chemical analyses.Sample pH,salinity,and dissolved
oxygen were measured using a pre-calibrated water quality sonde (YSI ProDSS).Turbidity was measured
using a nephelometer (Turner Designs)calibrated with 2 and 20 nephelometrie turbidity units (NTU)
formazin standards.
Field Sample
(+temperature QC)
1 or 1 0 ml PBS+Enterolert
Up to 500 ml Filter
Remainder YSI Probe
IV
IDEXX
Incubate and count
Preservative
DNA/RNA Shield
-80 "c for MST
Collect data:pH,lab temperature (QC),
salinity (psu),turbidity (FNU),dissolved
oxygen (mg/L)
Figure IV.2:Sample splitting protocol to accommodate enterococei analysis,filters for MST,and physical-
chemical analysis of water samples.
Statistical analysis of the data was based upon two tests,the Kr uskal Wallis Test which compares the medians
betw een two or more groups of samples (e.g..in-person runoff.field-staged bottle.versus puddles)and the Mann
Whitney U Test which compares medians between two groups only.Groups of data were considered statistically
different for p values less than 0.05.
52
IV.1 GROUNDWATER
Groundwater sample collection was facilitated through the drilling of shallow groundwater wells using direct
push technology.The company contracted for the well drilling (JAEE Environmental Service Inc)uses a
retractable groundwater sampler mounted on the back of pickup truck.The groundwater sampler is
decontaminated between each use by flushing with clean tap water.To collect samples,the groundwater sampler
(diameter of 1 and¾inches)is drilled to a depth 1 foot below the groundwater's surface.Upon reaching the I-
foot groundwater depth the sampler and drive rods are pulled back to expose the screen (0.007 slot size)allowing
for groundwater collection from the upper 1 foot.The upper 1 foot was chosen as prior studies showed that the
upper layers of the water in the stormwater conveyance system had the highest levels of enterococci.A new 3/8-
inch diameter tubing was placed inside the sampler and groundwater was then pumped using a peristaltic pump
for 5 minutes to allow for clearing of the well.After the purge cycle,1 L of groundwater sample was collected
into pre-sterilized and pre-labeled polypropylene bottles.Samples were placed immediately within a cooler on ice
and transported to the laboratory at the end of each collection day for immediate processing.
The original goal was to collect 8 to 12 groundwater samples.However,the UM research team decided to extend
the sample collection program to select 31 sites (Figure IV.3).Sites were selected to obtain a uniform distribution
of groundwater throughout the contributing watershed.Some sites were located near gravity sewer systems (site
names start with the letter G),some were located near force mains (site names start with the letter F),and some
sites were located near stormwater conveyance systems (site names start with the letter R).Upon the selection of
the sites,efforts focused on identifying the underground utilities.This required "white lining"a 15 by 15-foot
area of the site where drilling was to take place.Upon white lining the areas,the County 811 underground utilities
hotline was contacted and given the site locations so that all utility contractors in the area could visit the site and
mark the location of the underground utilities.After the marking of the utilities through 811,a contractor through
the well drilling company performed ground penetrating radar of the sites using both handheld and roller units to
confirm the location of the underground utilities and identify specific areas (within a l-foot diameter)that were
clear for drilling.Among the 31 sites evaluated,only 26 were deemed to have enough clearance from utilities to
allow for safe drilling.Details about each sample location including photos are provided in Appendix C.
In addition to utilities identification,a right-of-way permit was requested and granted (RWP0724-12376)to
temporarily block traffic during the well drilling process.The local community was informed of planned activities
through the CMB's Constant Contact notification system.Ground penetrating radar was conducted on July 22,
2024.Groundwater sample collection occurred over a period of 3 days,on July 23,24,and 25.During these days
samples were collected from all 26 viable groundwater drilling sites.
Enterococci levels for the 26 groundwater samples ranged from below the lower detection limit (<l 0 MPN/100
mL)to above the upper detection limit (>24,196 MPN/100 mL).The arithmetic and geometric means were 1,100
and 61 MPN/100 mL,respectively.The median was 68 MPN/100 mL (Table IV.1).Given the large range of
enterococci in the groundwater samples,outlier statistical tests were conducted including the Rosner test and the
Q-test.The Rosner test evaluates outliers by comparing the data point in question relative to the mean.The Q-test
evaluates outliers by comparing the data point in question relative to the maximum and minimum value.For both
statistical tests,four outliers were identified.The outliers were F7 (>24,196 MPN/100 mL),F9 (1,337 MPN/100
mL),Fl (794 MPN/100 mL),and Gl 7 (761 MPN/100 mL).
The spatial distribution of the data indicates a groundwater outlier (hotspot)at the end of 75"Street near the drop
off area of the BBE (site F7).The three additional outliers extend from east to west along 73"Street.The
easternmost outlier is located under the parking lot between 72 and 73"Street and between Harding and Collins
A venue (site Fl),a location with considerable underground sanitary sewer infrastructure.Additional hotspots
were found at 73rd Street and Dickens (site F9),and at 73""Street and Wayne Avenue (site G17)(Figure IV.3).
Visual inspection of the distribution of enterococci in groundwater suggest both low and high levels of
53
enterococei throughout the area.Enterococci levels in groundwater within Parkview Island were not statistically
different than the levels observed to the east on the main island of Miami Beach (p=0.58).
77h St
biasyne
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Park
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Legend,Groundwater
Enterococci Levels
o Less than 10
o 10-60
0 60-110
110-150
0150-230
@ 230-260260-1440
@@1440 -24196
7nd St 720d st
Figure IV.3:Spatial distribution of enterococci levels in groundwater samples with an emphasis on the outliers (sites F7.F9.
Fl,and G 1 7)identified by reel circles.The size of brown circles is proportional to the enterococci levels.Enterococci levels
at each location sampled are also indicated by the numerical value next to the brown circle.Site F7 located immediately
adjacent to the northeast end of the PVC (near the BBE school drop off location)was characterized by the highest levels of
enterococci by orders of magnitude above other sites (·24.196 MPN/I00 mL).Sites F9 (1.337 MPN/10O mL).FI (794
MPN/I00 mL).and G17 (761 MPN/10O mL)located along or immediately to the south of 73'Street were also elevated and
considered outliers.
54
Table IV.I:Enterococci levels for the UM samples (MPN/100ml)including groundwater.stormwater.
and PVC canal samples.Since two dilutions were used resulting in different levels of detection,data
were analyzed two different ways called "All and "Within Detection Limits (DL)".For "AIT.which
considers all samples,samples analyzed using a I mL dilution and measuring at values greater than
24.196 MPNI00 mL were set to >24.196 MPN/I00 mL so that all samples have the same frame of
reference in terms of the upper detection limit.For "Within DL",only samples were considered that
were within upper detection limits.All samples that were <l 0 MPN/100 nl.L were set to 10 MPN/l 00
mL for computation purposes.
N Min Max Median Avg.Geo Std.Coeff
Mean.Dev Var.
Groundwater 26 <10 >24.196 68 1.10I 61 4,721 4.3
PVC at BBE 7 740 198.630 2.720 33.096 5.508 73.232 2.2Outfall
Runoff
In-Person 67 740 >24,196 >24,196 18.,644 14,996 8.025 0.4(All)
I-Person 46 740 241.960 22.030 66.968 27.426 77.048 1.2(6within DL)
Puddles 29 861 >24,196 >24,196 18,922 15.259 7,704 0.4(All)
Puddles 20 861 173,290 24.196 30.650 18,131 35,858 1.2(within DL)
Field-Staged
Bottles 11 443 >24,196 >24,196 17.221 12,502 8,742 0.5
(All)
Field-Staged
Bottles 7 443 24,196 19,863 16.188 11,337 8,922 0.6
(ithin DL)
Overall 113 443 >24.196 >24.196 18,982 15,236 7,902 0.4(All)
Overall 79 443 241.960 19.863 55.633 22.365 68.666 1.2(within DL)
55
IV.2 STORMWATER
Stormwater samples were collected throughout the catchment using one of three methods.All three methods of
sample collection focused on collecting samples at street level prior to entering the stormwater conveyance
system.By collecting the samples at street level,we were able to eliminate potential groundwater contributions
from samples collected underground from catch basins and stormwater conveyance pipes.The three methods of
stormwater sample collection are referred to as:
•In-person runoff samples.These are samples collected at the inlet to stormwater catch basins during
active rainfall events.During any rain event,up to 8 consecutive samples were collected.Sample
collection during active rainfall required the removal of the manhole cover or grate to allow for access to
the stormwater as it was falling from the street into the catch basin.This sample type required that the
sampling team remain on-site prior to and during a rain event.A total of 67 in-person rain samples were
collected.
•Field-staged bottle samples.These are samples collected by placing a bottle,tied to a chain,immediately
under the grate of the storm drain.Not all storm systems were fitted with grates.This type of sampling
allowed the research team to place bottles under grates during the morning prior to a rain event,and then
collection of the field-staged bottle sample after the rain event later that same day.A total of 11 field-
staged bottle samples were collected.
•Puddle samples.Puddle samples are samples of standing water that are collected immediately after a rain
event.They represent water that can be potentially carried to the stormwater catch basins.A total of 29
puddle samples were collected.
Stormwater samples were collected during 7 different sampling days.Sampling dates were determined based
upon weather forecasts.Days with high probability of forecasted rainfall were chosen for sample collection.
Details about the location,sampling date,and sample collection method for each stormwater sample collected is
provided in Appendix C.
Results show that all stormwater samples,regardless of sample collection method,were characterized by elevated
levels of enterococci (Table IV.I,Figure IV.4).The medians and geometric means of in-person runoff samples,
field-staged bottle samples,and puddle samples were all in the tens of thousands ofMPN/100 mL.The
enterococci levels between these different methods of sample collection were not statistically different (p =0.95).
Discussions that follow,therefore describe the stormwater enterococci results for all three sampling methods
combined.Overall,the minimum enterococci concentration observed was 443 MPN/100 mL,with a maximum of
>241,960 MPN/100 mL.The arithmetic and geometric mean for all samples collectively was 55,600 and 22,400
MPN/100 mL.The median was 19,900 MPN/100 mL.The levels of enterococci observed in the stormwater were
statistically higher than the levels observed in groundwater (p<0.001).The distribution of elevated enterococci in
stormwater was uniform throughout the catchment.The levels observed on Parkview Island were not statistically
different than the levels observed to the east on the main island of Miami Beach (p=0.86).
56
Bis€aye
f«rentaty
park
I
£,»241960 s241960e~;;:~::rv ·•2419.
7
'.29970 1>24196h16thSt 46110
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Legend,Stormwater
Enterococci Levels
0 861 -4000
@ 4000 -10000
10000 -20000
@@20000 -30000
30000 - 7000o
@7000o -11oooo
@1uoooo-1so0ooo
.180000 -241960
Figure IV.4:Spatial distribution of enterocoeei levels in stormwater samples.The sizes of blue circles are
proportional to the enterococci levels.
57
IV.3 WATER FROM THE PVC
Two sets of samples were collected from the PVC.The first set of samples collected from the PVC corresponded
to hourly samples collected at the Kayak Launch on August 15,2024 (Section IV.3.a).Hourly sampling was
conducted from 6:00 am to 5:00 pm at three depths,at the surface,at I-foot depth,and at 5-foot depth.Samples at
I-and 5-foot depths were collected using a peristaltic pump with new dedicated tubing fitted with a weighted
nozzle which drew water at the designated depth.Samples collected at the Kayak Launch were labeled with a
"K S","K O ",and "KF ",representing surface,I-foot,and 5-foot depths,respectively,followed by a number
representing the hour during which the sample was collected.A total of 35 samples were collected at the Kayak
Launch.One sample at the 5-foot depth could not be collected.Results from this (2024)hourly sampling effort
were compared to the hourly sampling effort conducted during the 2022 study to evaluate differences in water
quality.
The second set of samples from the PVC were collected from a large (24 inch)outfall which corresponded to the
stormwater system that drains the BBE property (Section IV.3.b).The attention drawn to this outfall was due to
high levels of enterococci in groundwater from site F7 (BBE school drop off area).Samples collected from the
PVC near the BBE outfall were labeled "CS"followed by a number corresponding to different dates of sample
collection (e.g.,Cl to C7 collected from August 5 to September 19,2024).A total of 7 samples were collected at
the water's surface from the PVC at the BBE outfall.
IV.3.a Results from sampling at the Kayak Launch
For the UM data set,results show similar median values (216 to 388 MPN/100 mL)regardless of sampling depth
(Table IV.2)(p=0.17).However,the arithmetic average is highest for the samples collected at the surface (1,381
MPN/100 mL)compared to those collected at 1 foot (249 MPN/100 mL)and at 5 feet (690 MPN/100 mL).
Similarly,the geometric means were highest at the surface (423 MPN/100 mL)compared to those at 1 foot (180
MPN/100 mL)and at 5 feet (393 MPN/100 mL).Overall,the enterococci levels at the surface of the PVC were
characterized by high variability (standard deviation of 2,620 MPN/100 mL)compared to the variability at lower
depths (<180 MPN/100 mL).The variability was statistically higher at the surface compared to the variability at
depth (p<0.001)based upon the Levene's test which was used to compare the standard deviation values.
The values observed for the UM data set were consistent with those observed within the CMB and Surfrider data
sets (Table IV.2).The medians of all three data sets were in the 200 to 400 MPN/100 mL range (p=0.35).
Similarly,the geometric means were in the 300 to 370 MPN/100 mL range.The arithmetic averages observed in
the UM data set were lower than the arithmetic averages observed for the CMB and Surfrider data sets (690
MPN/100 mL compared to 2,100 and 2,500 MPN/100 mL).This may be because of the dry conditions (six prior
days with no rain)preceding the UM sampling date,reducing the influence of stormwater within the PVC.
The hourly time series (Figure IV.5)emphasizes the variability of the enterococci levels at the water's surface.
Enterococci levels were highest at the surface during the early morning and late afternoon hours,and the lowest in
the early afternoon.We attribute this trend to solar radiance effects where the heat and UV light from the sun
inactivated the enterococci at the water's surface,whereas water at greater depth was not as impacted by sunlight
allowing the enterococci to remain at constant levels.Pearson correlations were evaluated between enterococci
levels and sample elevation separated by surface,I-foot,and 5-foot depths.Results show statistically significant
correlations for the surface and I-foot samples.When evaluating correlations with solar radiance,significant
correlations were observed for the 5-foot samples only.
The reason for the very elevated levels at the surface is possibly due to buoyancy effects with freshwater (from
stormwater runoff)floating over the saltier water (as documented during the prior study conducted during 2022,
58
Montas et al.2023).As reported in Section IV.2,stormwater runoff has elevated levels of enterococci.Towards
the end of the hourly sampling period,from 3:45 pm to 4:30 pm,0.18 inches of rainfall were measured from a
rain gauge brought to the Kayak Launch site.The increase in enterococci during the 4 pm and 5 pm periods may
be associated with some stormwater entering the PVC from this small rainfall event.However,it is uncertain
whether this small amount of rainfall was sufficient to induce flow from the streets towards the catch basins.
Alternatively,the increase in enterococci bacteria can be possibly due to "rebounding"at the surface due to less
intense solar radiation towards the later hours of the afternoon.When considering both sample elevation and solar
radiance,correlations were significant for the I-foot and 5-foot depth samples.Overall,this analysis suggests that
water surface elevation and solar irradiance are environmental factors associated with enterococci levels.In
general,high enterococci levels during the 12-hour sampling event were associated with high water elevations
and low solar radiance.
The plot of enterococci versus sample elevation (Figure IV.6)illustrates the same data as in Figure IV.5.In this
plot,it is emphasized that as the water elevation is higher in the PVC,the enterococci levels are higher.These
high-water elevations coincided with early morning and later afternoon hours when solar radiance was not
intense.Also,the levels of enterococci appear to converge at an elevation of -6to-7 ft NGVD88,with levels in
the 500 to 700 MPN/100 mL range.Overall,results emphasize that very different enterococci values would be
obtained depending upon the depth of the water samples collected and the hydrologic conditions.Although the
CMB and Surfrider data sets are consistent,as mentioned earlier,the difference in sample collection depths
corresponding to the CMB data set (1 foot)and the Surfrider data set (6 inches)could explain the more nuanced
differences observed in the two enterococci data sets (e.g.,the larger variability observed for Surfrider relative to
CMB).
The high levels of enterococci with high tide contrasted with what was observed during hourly sampling during
2022 (Montas et al.2023).Comparison of hourly sampling between the current 2024 study and the 2022 study
shows that the levels for both studies during non-storm conditions were elevated (Figure IV.7).During 2022,the
enterococci concentrations increased during low tide,while during 2024 the enterococci concentrations
decreased.This is the opposite trend and represents a potential underlying change in the source of enterococci to
the PVC.From a conceptual perspective,elevated levels of enterococci would be expected from sanitary sewers
during low tide as this is the time when groundwater predominantly contributes towards the PVC.Low tide is
when the hydraulic gradient (elevation between the groundwater and the PVC)is strongest favoring the
movement of groundwater "downhill"towards the PVC.The shift in pattern between enterococci
concentrations and tidal heights suggests a potential decrease in groundwater sources of enterococci to the
PVC between the 2022 and 2024 study periods.
Additionally,an important observation is that the enterococci concentrations during 2024,although elevated,
were lower than those observed during 2022.During 2024,the levels during low tide between storm events was
in the lO0's to l0's ofMPN/100 mL.This contrasts with the levels during 2022 which were in the several l00's
to l,000's of MPN/100 mL.This decrease during low tide conditions is significant numerically (p <0.001).
Although it appears that there may be a significant improvement in water quality in the PVC during low tide,the
levels were still elevated in 2024,efforts are still needed to identify and remove enterococci sources that
contribute at low tide during dry conditions.
Further analysis of the physical-chemical parameters measured at the time of hourly sampling showed no
statistically significant differences with water depth for pH,water temperature,nor dissolved oxygen (p>0.15)
(Table IV.3).However,statistically significant differences were observed with depth for turbidity (p<0.001)and
salinity (p<0.001 ).Mann Whitney U tests,used to compare sets of data,showed that for turbidity,the statistical
differences were observed between the surface samples and the 5-foot depth (p<0.001)and between I-foot and 5-
foot depths (p<0.001).No statistical differences were observed for turbidity between the surface samples and
samples collected at the I-foot depth (p=l.0).Overall,the water closer to the surface in the PVC (at the surface
59
and I-foot depths)were characterized by lower turbidities in comparison to samples collected at depth (5-foot).
For salinity,the Mann Whitney U tests showed that the salinity of the PVC water was statistically higher at the
surface compared to a I-foot depth (p=0.003)and compared to a 5-foot depth (p<0.001).Similarly,salinity at the
I-foot depth was high in comparison to the 5-foot depth (p<0.001).These results support the observation from the
2022 study which observed a fresher water layer floating atop a saltier water layer within the PVC.In this 2024
study,the variability of enterococci in the fresher water layer at the surface was higher than the variability of
enterococci at I-foot and at 5-feet.
Table IV.2:Enterococci level summary for the PVC Kayak Launch (MPN/100ml)for samples
collected hourly on August 15,2024 (UM data set).The UM data are summarized by water
sampling depth (water surface,I-foot depth,and 5-foot depth)and overall,considering all
depths.The UM data are compared against the summary statistics of the CMB data set
(monthly sampling between 2019-2024)and the Surfrider data set (weekly sampling between
2022-2024).
N Min Max Median Avg.Geo Std.Coeff
Mean Dev.Var.
UM
Surface 12 30 9,208 309 1,381 423 2,620 1.9
lfoot 12 41 538 216 249 180 176 0.7
5feet 11 187 651 388 418 393 146 0.3
Overall 35 30 9,208 350 690 308 1,580 2.3
CMB 65 <10 >24,196 297 2,113 370 5,392 2.6
Surfrider 150 <10 >24,196 324 2,484 370 6,086 2.5
60
Table IV.3:Enterococci level summary for the PVC Kayak Launch compared to physical-chemical properties of
the water.Data collected hourly on August 15,2024 (n=12 for surface,n=l2 for 1-foot,and n=l 1 for 5-feet).
Surface 1-foot 5-feet
arith.geo.median arith.geo.median arith.geo.medianmeanmeanmeanmeanmeanmean
Enterococci 1381 423 309 249 180 216 418 393 388(CFU/l00mL)
Water.Temp 33.l 33.0 32.6 33.l 33.1 32.8 33.3 33.3 33.2C)
pH 7.70 7.69 7.52 7.63 7.63 7.55 7.61 7.61 7.58
Dissolved Oxygen 6.50 6.42 6.02 6.54 6.48 6.25 6.55 6.50 6.25(mg/I)
Salinity 31.65 22.36 34.73 35.62 35.60 35.90 36.59 36.59 36.60(ppt)
Turbidity 1.29 1.22 1.20 1.26 1.20 1.15 4.80 4.22 4.00(ntu)
61
I
~----------------~-SolarRadiance t !!r I
--200 g>---~~~-~--~---,--~--~--~--~-~-~~--~--+0 ~
,moo+~Gan..a...n..n.a...a.a.a.al.T"°E ,l 2,0g1oo
:1o g
2 na1000.0 ;
2 1o$
10 -o 2.0 58e
is 3.0%
6:00AM 7.00AM 8.004M1 9.004M 1000AM 1100AM 12.00FM 1:00PM 2:00PM 3.00PM 4:00PM 5:00PM guIdTi
Surface Ore FOOL Five Feet ----Threshold Elevation of Water Surface (ft)
Figure IV.5:Time series of enterococci results from samples collected hourly from the PVC at the Kayak Launch
at three different water depths on August I5,2024.Superimposed as a dashed line is the 70 MPN/100 mL
guideline threshold (referenced to the left axis),and as a solid line,water elevation in units of ft NGVD88
(referenced to the right axis).Top panel shows hourly average solar radiance during the time of sampling.Solar
radiance data from Miami-Dade Weather Stem Station listed in Table II.2.
Enterococci (MPN/1O0 mL.)
-I
5 'csi-2E;·s
OJC.E%6
I0 II)I0u0 I 00I0
-·-6,00 AM
-7:00 AM
8:00 AM
0:00 AM
-+-1000 AM
-1L.00 AM
a12:00 PM
-+1:00 PM
-·2:00 PM
-+3:00 PM
-·4:00 PM
-·5;00 PM
-8 -'----------------------~
Figure IV.6:Enterococci versus water sample elevation in the PVC at the Kayak Launch.Samples collected
hourly on August 15,2024.Results show that when water elevation is higher the concentration of enterococci at
the surface is also higher.The high-water elevations also coincided with very early morning or late afternoon
hours when solar radiance was low.
62
Table IV.4:Pearson correlations (R2)between enterococci concentrations versus water surface elevation of the
PVC,versus solar radiance,and versus elevation of the water sample combined with solar radiance.Solar
radiance values corresponded to hourly averages.Analysis was separated by depth of water collected (surface,I-
foot,and 5-foot).Correlations are considered significant for p values less than 0.05 (highlighted in bold font).
Sampling Point Elevation in Solar Radiance Elevation and Solar Radiance
PVC
Surface Samples R2 =0.36 Solar radiance (surface R2 =0.24 Elevation of surface R2 =0.37
p =0.038 samples only)p =0.11 samples AND solar p =0.12
radiance
One-Foot Depth R2 =0.41 Solar radiance (one-foot R2 =0.12 Elevation of one-foot R2 =0.65
Samples p =0.024 samples only)p =0.26 samples AND solar p =0.009
radiance
Five-Foot Depth R2 =0.32 Solar radiance (five-foot R2 =0.54 Elevation of five-foot R2 =0.57
Samples p =0.068 samples only)p =0.010 samples AND solar p =0.033
radiance
1,500 ------------------------------------~1.5
00-+1,000ze,
"·ou 5ooe»-rl
»MPN 2022 -MPN 2024
o Tld<Height 2022 O Tld<H<lghtr /\••
o--/'-•'..-0 -1--
o .....,
0 -0
2022 o
0
0
'r ow/o nL
6:00
1.0 --00o0.5 zo.o
d±0.5 Z0:;:
-1.0 S±al-1.5 ;£-2.0
12:00
Time (October 18.2022 and August 15.2024)
-2.5
18:00
Figure IV.7:Comparison of hourly data during dry conditions and low tide for samples collected at the Kayak
Launch during 2022 (October 18) and during 2024 (August 15).Data from the year 2024 is shown by the thick
lines and data for the 2022 data set are shown by the thin lines.Data presented for enterococci (left axis and black
lines)and water surface elevation of the PVC (right axis and aqua lines).Heavy blue arrows illustrate the
difference in enterococci levels between the 2022 and 2024 data sets.
63
IV.3.b Results from sampling PVC site CS (Outfall at BBE)
Results from sample collection from the PVC at the BBE outfall showed elevated levels of enterococei.The
minimum and maximum were 740 MPN/I00 mL and 198,630 MPN/I00 mL,respectively.The arithmetic and
geometric means were 33,100 and 5,510 MPN/I00 mL,respectively.The median was 2.720 MPN/100 mL (Table
IV.5).
The median concentration at the BBE outfall was between the median observed for stormwater (on the order of
tens of thousands of MPN/I00 mL.Table IV.I)and the median observed for the PVC at the Kayak Launch
(overall median of350 MPN/100 mL,Table IV.2).The median level of enterococci at the BBE outfall was
statistically higher than the levels observed at the Kayak Launch (p=0.018).When considering the maximum
values (shown in Figure IV.8).the differences in concentration between the BBE outfall and the Kayak Launch
are further emphasized.These results support that the BBE outfall is a source of enterococei to the PVC.See
Chapter VI for details on how the CMB is addressing this source.
Table IV.5:Data for samples collected from the PVC at the BBE outfall.
Site ID Sampling Date Sampling Time Enterococci Level
(MPN/1OO mL)
CSl Aug.5.2024 12:35 PM 17.329
CS2 Aug.20,2024 4:27 PM 198.630
CS3 Aug.23,2024 1:29 PM 980
CS4 Aug.23.,2024 3:30 PM 740
CS5 Aug.29.2024 2:30 PM 2,720
CS6 Sep. 19,2024 3:36 PM 2.620
CS7 Sep. 19,2024 4:15 PM 8.650
Median 2.720
Arithmetic Average 33.100
Geometric Average 5.510
-BBE Outfall Samples
layak Launch Samples
9"}1 i
Figure IV.8:Spatial distribution of enterococci concentration for samples collected from within the PVC.The
size of the circles corresponds to the maximum concentration of the enterococei observed at the respective sites.
The numerical values next to the circles represent the maximum enterococei concentration in MPN/100mL.
Samples collected at the PVC water's surface correspond to dark orange.Light orange circles correspond to
samples at the Kayak Launch at I-foot depth.The yellow circle corresponds to samples collected at the Kayak
Launch at 5-foot depth.
64
IV.4 COMBINED RESULTS FROM UM SAMPLES
The combined results from samples collected by the UM are illustrated in Figures IV.9 and IV.IO.Results show
the relative distribution of enterococci concentrations within the different types of water samples collected.
Results show that groundwater enterococci concentrations tend to be the lowest among all sample types.The
median levels of enterococci in groundwater were statistically lower than stormwater (p<0.001)and in the PVC
including both the Kayak Launch (p<0.001)and the BBE location (p<0.001).Groundwater hotspots were
observed at the end of 75 street at the pickup area for the BBE plus three additional hotspots along 73'Street.
Stormwater was characterized by elevated enteroeocei levels consistently throughout the catchment.The median
levels of enterococci in the PVC at the Kayak Launch (p <0.001)and,at the BBE (p =0.010),were both
statistically lower than stonnwater.
Within the PVC,water collected at the surface had higher enterococci levels than water collected at depth.When
evaluating the arithmetic averages,levels of enterococei were highest in the surface water.However,when
evaluating the medians,no statistical differences were observed within the PVC with water depth (p=0.17).
Additionally,the BBE outfall was a hotspot for enterococci within the PVC.When comparing the two PVC
locations,the enterococei levels collected at the Kayak Launch were statistically lower than the enterococei levels
in the samples collected from the BBE outfall (p=0.018).
Legend
•Stormwater
@Groundwater
@Pv,surface
)PVC,1-foot
)PVC,5-foot
9241960 129970 ,>24196.g"ees gs:
145 .25810 5830.16790 A <10 ...•.75•h Street
•
98630 40 ,98630 .... "•o97w«<1026131•.2997 ••.,,
85 s<to <1
+524196 ?a24196 l 120330 -·24196.41960 ;
•
24196.>241960 •11590....•<10 a .,...74••Street-@ ta ,
228 .17329+o.Sea«so I«•'1>241960 ·•>Z4l9GO l 15520 2415
1076'11\253 .S040 "<la•.>24195""73••streete%1337 'To1ot
>24196
3609 1 2080124196
6"e1soe$
"
i3
•
19~~~
61310
e"o
•••29970
11199
72/street
Figure IV.9:Spatial distribution of enterococei concentrations in groundwater,stormwater,and water from the
PVC.The size of the circle is proportional to the enterococci concentration.The numerical values represent the
maximum values at each site.
65
a)General categories b)Stormwater Samples c)PVC Samples
,.....,e 20000Groooo 10000.......5000-•z ••±1ooo -5000
~
.
2000@1000>100DI
'500 100oB50
%q>10 2000O1000'-a 50o1CLUKaya¥B E Surface SurfaceGroundwaterStormwatertau«l Outfall Puddles Bottles In-Porson 1 foot 5 feet(BB8E)canal KL
Figure IV.l 0:Box and whisker plot for the enterococci data collected as part of this current study (UM 2024
samples).Boxes represent the upper and lower quartile,the error bars represent the minimum and maximum
values when excluding outliers,and the x symbols outside the error bars represent outliers.The central line in the
box represents the median,and the square represents the mean.Panel a categorizes enterococei data by
groundwater,stormwater.PVC water at the Kayak Launch,and PVC water at the BBE outfall.Panel b separates
the storwater samples by method of sample collection (puddles,field-staged bottles,and in person).Panel e
corresponds to the enterococei measured within the PVC at the BBE Outfall (surface sample)and at the Kayak
Launch by depth of sample collection.
66
IV.5 STORMWATER AND PVC DAT A IN THE CONTEXT OF THE LITERATURE
A literature review was conducted to better assess whether the concentrations of enterococci observed in
stormwater within the PVC and the PVC catchment were within the norm of other studies.Studies were separated
into three groups:studies that evaluated roof runoff or runoff from experimental plots (Table IV.6),studies that
evaluated waterways that were highly impacted by stormwater runoff (Table IV.7),and studies that evaluated
stormwater runoff collected from streets prior to entering larger waterways (Table IV.8).
For roof runoff (Table IV.6),levels ranged from single digits to the low thousands ofMPN/100 mL.For the study
conducted for roofs in Miami,the median concentration was 870 MPN/100 mL,and the arithmetic average was
1,200 MPN/100 mL.These values are on the low end in comparison to the enterococci in the stormwater samples
collected from the PVC catchment.Experimental studies conducted to evaluate runoff from a roof,asphalt,
permeable pavers,porous concrete and asphalt,again confirmed the relatively low levels observed in roof runoff.
Of interest were the relatively higher levels in permeable pavers and the observed lower levels from porous
concrete and asphalt suggesting that pavement type may assist in reducing enterococci in stormwater runoff.For
all cases listed in Table IV.6,the runoff from the experimental systems (Selvakumar and O'Connor 2022)were
all less than the values observed in stormwater runoff within the PVC catchment.
Table IV.6:Enterococci Concentrations in Roof and Pavement Runoff Under Experimental Conditions
Concentration
Reference Matrix Location Number of MPN or CFU/100 mL)
Samples Min Max Median Average
Fort Collins,TX N=26 5.1 2,420 540 1,040
Alja'fari et al.Tucson,AZ N=l7 16 2,420 1,690 1,370
2022 Roof Runoff Baltimore,MD,
USA N=l9 9.5 2,420 130 523
Miami,FL N=l7 24 2,420 870 1,200
Roof runoff N=42 1 1,100 9 73
Asphalt runoff N=79 1 48,400 24 1,180
Selvakumar and Permeable Pavers N=83 I 24,196 177 1,210typeIO'Connor Permeable Pavers Edison,NJ
2022 type 2 N=47 I 24,196 30 864
Porous concrete N=36 <l 563 15 68
Porous asphalt N=84 <l 55 I 6
For the environmental waters highly impacted by stormwater runoff (Table IV.7),levels observed were variable
with maximums per study ranging from 13,000 MPN/100 mL to values upwards of 480,000 MPN/100 mL.The
sites characterized by the lower maximums (New Orleans,LA and Norfolk,VA)were characterized by medians
in the l ,000's MPN/100 mL range.The waterway with extreme high levels of enterococci (Southern California)
were impacted by runoff from recreational lands that included horse stables.The authors of the Southern
California study (Tiefenthaler et al.2011)imply that the cause of the elevated concentrations for this watershed
was due to horse manure.In comparison,the results for the PVC were within range of the low end for these
studies.The median for the PVC samples was on the order of l00's ofMPN/100 mL which is less than the
medians for the New Orleans and Norfolk studies.Overall water quality within the PVC is within the norm
observed for highly impacted waterways within the U.S.
67
Table IV.7:Enterococci Concentrations in Environmental Waters Highly Impacted by Stormwater Runoff
(representative set).Results for samples from the PVC in bold font.
Concentration
Reference Matrix Location Number of (MPN or CFU/100 mL)
Samples Min Max Median Average
Stormwater from 2 storm events
Jahncke Canal (n=8,n=l0)
Jeng et al.which collects New Orleans,Samples 440 13,000 4,300 4,9002005stormwaterfromLAcollectedfrom
urban areas stormwater
pumps
Macias-Floodwaters from
Tapia et al.Lafayette River in Norforlk,VA N=23 30 >24,000 1,200 6,300
2021 Chesapeake,Bay
Creek from Ballona
highly urban Creek,N=l0 NA"230,000°NA NACalifornia
Tiefenthaler,watershed Highly Urban
et al.(2011)Runoff from
recreational land Southern N=20 NA 480,000"°NA NAuse(horse California
stables)watershed
UM2024
study,CMB
(top row)and PVC canal from Miami N=20 10 >24,200 160 434
Surfrider Feb'23 to Sep'24 Beach,FL N=83 10 >24,200 430 2,960
data set
(bottom row)
"NA=Not Available
Peak concentration read from graphs
For street-level stormwater samples (Table IV.8),average values were variable.The stormwater collected from
the watershed in Sweden had the lowest enterococci levels among all studies evaluated.For watersheds in New
Jersey (Selvakumar and Borst 2006),enterococci averages were in the 1,000 to 6,600 MPN/100 mL range.For
the study in North Carolina,the maximum level of enterococci observed was 9,700 MPN/100 mL.Studies in
Michigan (Gannon and Busse 1989,Hathaway et al.2010)and Texas (Pan and Jones 2012)show enterococci in
street-level stormwater with averages between 6,000 to 25,200 MPN/100 mL.Of note,Hathaway et al.(2010)
implicated dogs as the source in their study.The one study conducted from a dog beach in Miami impacted by
several local sources found average levels above 15,100 MPN/100 mL (Wright et al.2011).One study in
Blacksburg,VA (Jacobs et al.2019)found extraordinarily high levels of enterococci in experimental plots where
fertilizer was added (14,000,000 MPN/100 mL).The values observed in these studies suggest that the average
enterococci in stormwater from the PVC catchment (55,600 MPN/100 mL)is on the high end but within
levels that would be observed from impacted catchments especially those impacted by animal fecal waste
(e.g., manure or dog waste).Also of interest is the possibility that elevated enterococci levels may be
exacerbated by fertilizers.
68
Table IV.8:Enterococci Concentrations in Stormwater Runoff.Results from stormwater samples collected from
the PVC catchment are in bold font.
Concentration
Reference and Matrix Number of MPN or CFU/100 mL)
Location Samples Min Max Median Average
Storm drain from recreational 10 16,000 NA"1,440area(21 %impervious)
Galfi,et al. (2016)Storm drain from residential area 6 to 7 storms per 10 9,000 NA 730°
Ostersund,(47%impervious)site type with 5 to
Sweden Storm drain from mixed land use 15 samples per 180 90,000 NA 3,930°(53%impervious)storm
Storm drain from institutional 10 30,000 NA 870°(hospital)area (85%impervious)
Storm drain from high density N=72 NA NA NA 3,200-
Selvakumar and residential (65%impervious)5,000
Borst 2006 Storm drain from low density N=80 NA NA NA 1,000-
Monmouth residential (17%impervious)2,200
County,NJ Landscaped commercial N=73 NA NA NA 4,000-
6,600
Converse,et al.Catch basins upstream of 5 storm events from 275 97195siteswith3to6(2011)stormwater outfalls (medium-samples collected (average of (average of 5 NA NA
Dare County,NC density residential area)per site per storm 6 samples)samples)
Gannon and Busse Mouth of storm drain (Allen N=19 <50 340,000 NA 6,400°drain,highest)(1989)Mouth of storm drain (NorthAnnArbor,Ml Campus drain,lowest)N=9 1,700 34,000 NA 91,000°
Pan and Jones
(2012)Stormwater detention basin N=15 NA NA 10,100 12,572%°
Houston,TX
Wright,et al.Stormwater runoff from channel
(2011)on a dog beach impacted by N=34 690 >32,600 NA >15,100
Virginia Key,FL parked cars,open garbage bins,
and dogs
Hathaway et al.Stormwater from residential 20 storm events 182,000°(2010)watershed (35%impervious).(average of 10 1,300°655,460°12,300 25,200
Raleigh,NC Implicate dogs as a source.samples per storm)
Six storm event
Jacobs et al.Runoff from experimental land samples from 27
(2019)plots with inorganic fertilizer but plots evaluated with NA 14,000,000 NA NA
Blacksburg,VA no manure added and without dairy
manure
UM 2024 study Stormwater from puddles,field-
Miami Beach,FL staged bottles,and in-person N=79 (within DL)440 241,960 19,860 55,630
sampling
NA=Not Available
b Event Mean Concentration (EMC)
c Geometric mean.Arithmetic means not provided
d Mouth of storm drain with lowest level of enterococci was found to have a chlorine residual making this site (Fuller Drain) non-
representative of a storm drain not receiving treatment.
The study focused on reporting EMC,The absolute maximum value among the estimated 200 storm samples was 655,460 MPN/100
mL (Hathaway et al.2015).
69
CHAPTERV
RESULTS FROM MICROBIAL SOURCE TRACKING
70
C HA P T ER V
RESULTS FR O M M IC R O B IA L SO UR C E T RA C KI N G
The CMB has used MST to evaluate the potential sources of enterococci to the PVC.Their earlier data showed
that dogs and,to a lesser extent,birds,and humans,were sources to the PVC.A similar approach was
implemented by Surfrider who found evidence human and,to a lesser extent,dogs,as sources.Our goal was to
measure groundwater and stormwater independently for MST,to assist in confirming the source of enterococci to
the PVC.Plus,samples from the PVC itself were also measured for MST to reconfirm sources upon entering the
PVC.This chapter provides a brief description of the methods (Section V.l)followed by the results from the
2024 UM MST sampling effort,one of the major efforts of this current study (Section V.2).The last section
(Section V.3)compares the results from all samples analyzed by qPCR including correlations between the
culture-based and qPCR measurements of enterococci and correlations with the individual MST markers.
V.l SAMPLE PROCESSING FOR MST
The basis of MST analysis is the laboratory qPCR procedure.The markers targeted through qPCR include four
that focus on identifying specific animal sources (human,dog,bird,and gull)plus one that focuses on analyzing
for enterococci (EnterolA),to be used for comparison against the enterococci measured by culture.The
laboratory used to measure markers by qPCR was the microbiology laboratory led by Drs.Chris Sinigalliano and
Dr.Maribeth Gidley at NOAA-AOML.Preprocessing of the samples was conducted at UM by preparing filters as
described in Chapter IV.These filters were stored at UM at -80 °C in lysis buffer (DNA/RNA Shield by Zymo
Research Corp.)to preserve the DNA. The filters chosen for MST analysis were selected based upon the sample
type and the enterococci levels that were measured by culture from the sample split.A total of 48 samples were
delivered to the NOAA-AOML laboratory on September 6,2024,and an additional 30 samples were delivered
during November 2024.The samples chosen for MST analysis included all the groundwater samples (n=26), 9
PVC samples at the Kayak Launch,5 PVC samples at the BBE outfall,37 stormwater samples,and l blank.The
canal samples corresponded to three depths collected during dry conditions at the early morning high tide (n=3),
mid-day low tide (n=3)and shortly after a storm event in the late afternoon (n=3).The five samples chosen from
the outfall to the BBE were the first five (of a total of seven)collected.The stormwater samples were chosen from
the watershed with a preference of including samples that were collected in-person.Twenty stormwater samples
were collected in-person,11 were field-staged bottle samples,and 6 were puddle samples.A complete list of the
samples analyzed for MST is given Table V.1. Locations for each sample collection are detailed in Appendix C.
Sample analysis at the NOAA-AOML laboratory included eDNA extraction and purification with a Kingfisher
Flex instrument on October 2,2024 (first batch of 48)and December 16,2024 (second batch of 30).This was
followed by quantitative polymerase chain reaction (qPCR)amplification of five diagnostic target DNA sequence
markers,using primers specific for human (HF 183-targets 16S rRNA gene of Bacteroides spp.),dog (DG3
targets 16S rRNA gene of Bacteriodes spp.),bird (GFD-targets 16S rRNA gene of Helicobacter spp.),gull
(Gull2-targets 16S rRNA gene of Catellicoccus marimammalium),and general total enterococci (Entero lA -
targets 23S rRNA gene of most species and strains of fecal-associated enterococci)fecal bacteria gene markers.
Environmental concentration results for qPCR measurements of each sample were normalized by the sample
filtration volume,sample lysate volume,purified eDNA elution volume,and template eDNA volume in the qPCR
reaction,thus allowing for the conversion of the results into units of "target gene copies"(gc)per 100 mL of
original environmental water sample (gc/100 mL).For the first 48 samples,results were released to UM by
October 28,2024,for human (HF183),dog (DG3),and bird (GFD),and on December 27,2024,for seagull
(Gull2)and general enterococci (EnterolA).For the second batch of 30 samples,results were released on
February 18, 2025.Additional details about the laboratory methods for qPCR analyses are given in Appendix D.
71
V.2 RESULTS FROM MST ANALYSIS
V.2.a Stormwater versus Groundwater as the Enterococci Source
Results from MST (Table V.1 raw data,Table V.2 summarized data,Figure V.1)emphasize that the source of
enterococci to the PVC is from stormwater not groundwater.The enterococci measurements by qPCR
(EnterolA)were all within detection limits (Figure V.2).For groundwater,the highest level of enterococci
measured by PCR was at site F7 (10'gc/10o L),consistent with the highest enterococci levels measured by
culture.All other groundwater samples measured at 103 gc/100 L or lower.In contrast,stormwater enterococci
levels by qPCR were much higher,from 10 to 10'gc/100 L,confirming the results observed for enterococci by
culture.Like enterococci by culture (Figure IV.9)the enterococci by qPCR were elevated in stormwater collected
throughout the watershed (Figure V.3).The contribution of stormwater as the source of enterococci to the PVC is
further emphasized by the results from the human and dog MST markers.The human (Figure V.4)and dog
(Figure V.5)source tracking markers were found predominantly in stormwater and PVC water,not in
groundwater.
V.2.b Dominance of Bird Marker
Among the MST markers,the bird marker dominated (Table V.1,Figure V.6,Figure V.8).Unlike the other MST
markers,it was found in all samples with the highest found within the PVC samples at the Kayak Launch (except
for one stormwater sample).This spatial distribution of the MST bird marker suggests that the major source of
the bird maker is "internal"to the PVC,which is consistent with the fact that the trees that border the PVC
provide habitat for birds.This distribution of bird MST marker is also consistent with the observation within the
PVC with higher levels observed during high tide.It is possible that bird fecal waste is deposited along the banks
of the PVC which washes in during high tide.In addition to PVC samples,the bird marker was found in
stormwater at elevated levels which suggests that birds are a source of enterococci throughout the catchment.Of
interest was the detection of bird marker in groundwater.Since birds were observed in the catchment only above
the ground surface,the MST marker measured in the groundwater is likely coming from stormwater impacted by
MST bird marker.The gull marker,which represents a subset of the birds,was observed intermittently only in
stormwater at a few isolated points in the watershed (Figure V.7).These results indicate that bird species other
than gulls are the dominant contributor to the bird marker observed.
Although bird waste is considered less infectious than human and dog waste,the levels of the bird marker were
elevated above the risk-based threshold (RBT) (22,500 gc/100 mL in the presence of detectable levels of human
marker)for acceptable levels of human illness.Thus,the high concentrations of the bird marker are
consistent with the high concentrations of culturable enterococci,suggesting that the PVC should not be
used at this time for full body contact recreational activities.
V.2.c Additional Sources Not Captured by MST Markers
The spatial distribution of the bird marker is not consistent with the spatial distribution of the culturable
enterococci.The bird marker is higher in the PVC canal compared to stormwater,whereas the enterococci by
culture concentrations are higher in stormwater compared to the PVC.This difference in spatial distribution
suggests that there is a source of enterococci to the stormwater and,ultimately to the PVC,that is not consistently
detected by MST.We hypothesize that this additional source of enterococci may be coming from "aged"
human and/or dog sources.This hypothesis is based upon two observations.First,field visits to the catchment
show evidence of dog fecal waste on the ground surface.Humans are also believed to be a potential source due to
72
the homeless populations throughout the catchment and the difficulties in getting access to sanitation facilities.
Additionally,historic sanitary sewer overflows could have contaminated sediments which can contribute towards
the persistence and growth of enterococci within sediments and possibly within the storm water infrastructure.
Second,as mentioned in Chapter I,the bacteria used to measure human and dog sources dies quickly in the
environment when exposed to aerobic conditions,whereas enterococci tend to persist.One explanation for the
inconsistency in the spatial distribution is that the MST signal from the stormwater is lost due to die-off of
the host bacteria,whereas enterococci remain culturable due to its ability to survive in the environment.
V.2.d Observations from Human and Dog Markers
For the 26 groundwater samples analyzed,no detections of human nor dog markers were observed except for site
R2 (Table V.l ).R2 had detectable levels of human marker but below the level of quantification.The lack of
human and dog marker was observed for the groundwater site (F7)which showed the highest levels of
enterococci.If human and/or dog markers are impacting groundwater,those signals are lost in the groundwater.
Therefore,the source of human and dog markers to the PVC is not from groundwater.
Additionally,for the PVC water at the Kayak Launch,no dog marker was detected.Human marker was detected
in five of the nine samples,although four of the five were below the levels of quantification.Only one of the nine
samples (a surface sample)showed levels of human marker above the limit of quantification,but the level
observed (110 gc/100 mL)was below the risk-based threshold for human marker alone (525 gc/100 mL).The
comparison of enterococci and human/dog source tracking markers for stormwater showed intermittent impacts
from humans and dogs.
For the PVC water at the BBE outfall,human and dog marker were detected in three of the five samples,although
all three of the human marker were below the limit of quantification.All three detections for the dog marker were
above the limit of quantification.
For the 37 stormwater samples analyzed,18 showed detectable levels of human marker with seven above the
limit of quantification,whereas 11 of the 3 7 stormwater samples were positive for dog marker,with eight above
the limit of quantification.All stormwater samples were positive for general bird marker,and four were positive
for seagull marker.These results suggest that stormwater in the PVC catchment is impacted by intermittent
detectable human and dog markers supporting these as contributing sources,in addition to bird sources.
V.2.e Spatial Distribution of All Markers
To further evaluate the results from MST,the data were plotted spatially in Figure V.8.The results emphasize the
dominance of the bird MST marker within the PVC canal with lower levels in groundwater and stormwater
throughout the catchment.However,for the time points of the samples collected in this study,seagulls do not
appear to be the predominant bird species contributing to the bird fecal contamination.The primary bird species
contributing to the observed bird fecal concentrations are not known.
The dog marker was detected above the limit of quantification in the middle and eastern portions of the catchment
at 76"Street,along Dickens and 74 Street,and in the parking lots at 75 Street and Ocean Terrace and 74"
Street and Harding Avenue.The human MST marker was primarily observed in the same locations as where the
dog marker was observed,with the exception that human marker was also observed on Parkview Island.It is
interesting to note the vicinity of positive detection of human markers closer to parks.Some parks do have access
to sanitation facilities,but these facilities may be closed at night limiting the time frame of public access.Before
conclusions can be drawn,further work is needed to evaluate access and utilization of sanitation facilities
within the catchment,especially at parks.
73
V.2.f Summary of MST Results
In conclusion,given the spatial distribution of the enterococci in stormwater versus groundwater versus the PVC,
and the results from MST,the major sources of enterococci have been identified as:
1)Dog fecal waste.Given that dog MST markers were intermittently observed in stormwater,we believe that
dog fecal waste is one of the contributors to stormwater enterococci throughout the PVC catchment and it
is transported to the PVC through the stormwater infrastructure.It is possible that the reason for the spotty
detection of dog MST marker in storm water (11 out of 3 7 samples)is due to the die-off of the host
bacteria that carries the MST marker gene.Dog marker was also observed in water at the BBE outfall (3
of 5 samples).No detections of dog MST were observed in groundwater nor in the PVC water at the
Kayak Launch.Due to the detection of dog MST in stormwater and BBE outfall and the visual
observation of dog waste on the ground surfaces within the catchment,some "fresh"and mostly "aged"
dog fecal waste is a likely contributor of enterococci to stormwater and ultimately to the PVC.
2)Human fecal waste.The human MST marker was generally not detected in groundwater except for 1 out
of 26 samples.This one sample was observed at low levels,as it was detected but not quantifiable.In
stormwater,18 of the 37 samples showed evidence of human MST marker,with seven of these samples
showing levels above the limit of quantification.Three of these samples exceeded the RBT.The
detections for human MST were found along the 73"Street area extending from Park View Island to
Byron Avenue with the sample exceeding the RBT collected at Carlyle and 73""Street.We suspect that
stormwater receives intermittent sources of "fresh"and "aged"human fecal waste,especially along the
73"Street corridor. Stormwater samples appear to have preferentially retained the human MST signal as
evidenced by the higher frequency of detection compared to the dog MST signal.Within the PVC at the
Kayak Launch,five of the nine samples showed detection of human MST marker,with only one being
quantifiable.Given the relative levels of human MST observed in the groundwater,versus stormwater,
versus the PVC,human waste is likely reaching the PVC through stormwater runoff.Since
stormwater originates at the surface,we believe the human signal in stormwater can be from one of two
sources.The first source can include humans who defecate on the streets which can include populations
without access to sanitation facilities such as homeless,or people who have chosen to not use or have been
rejected access to sanitary facilities.The second source may be from surface sediments that have been
contaminated by sewage overflows and are washed off during storm events and transported towards the
stormwater catch basins.
3) Bird fecal waste.The general bird MST marker (GFD)was detected in all samples analyzed,whereas only
four stormwater sites had significant detectable seagull-specific MST marker (Gull2).The highest levels
for the bird MST were observed in the PVC.The levels of bird MST in the PVC were above the RBT
given the detectable levels of human marker.It is likely that birds foraging in the area release their waste
directly into the canal or waste can also be released from nesting and wading birds along the shore which
can then be washed into the PVC during high tide or during storm events.It is believed that the seagull
fecal marker decays more rapidly than the general bird fecal marker,so a mixture of bird fecal inputs of
different ages may have had some contribution to the low seagull marker concentrations as compared to
general bird fecal marker concentrations.It could also be speculated that other types of birds (e.g.,
songbirds)might be more predominant in the area immediately prior to the time of sampling,especially
near parks or residential areas.The use of bird feeders may attract larger populations of non-gull birds
contributing to storm water and might encourage increased direct deposition of bird feces directly to the
shore area and water column of the PVC.The results from this study show that bird fecal waste is a
significant contributor to the PVC and the levels of bird waste are above risk-based thresholds.This
confirms the results from enterococci that the PVC water quality does not meet guideline levels for full
body contact recreational activities.
4) Potential natural background reservoirs of enterococci.It should be noted that the very high levels of
enterococci observed both by live culture and by qPCR are not likely to be fully explained by the levels of
74
human,dog,or even bird fecal markers observed during this study.Although there are significant
elevations of these markers (specifically bird marker)in many samples, in our opinion there are higher
observable levels of enterococci in many samples than can reasonably be accounted for by the levels of
the specific MST markers that were measured.Therefore,it should be considered that there might be
additional non-human-host fecal sources in the region besides the ones measured in this study.There is a
possibility of persistent populations of non-fecal enterococci associated with the environment
contributing to the enterococci loads,such as from sediments/soils,plants,or biofilms of hardened
infrastructure in the region.It would be worth following up with studies to evaluate regional
soils/sediments and catchment infrastructure to confirm potential background populations of persistent
enterococci and conditions under which they regrow.The prior UM study conducted in 2022 did measure
enterococci in the surface sediments,sediments along the channel banks,and sediments within the bottom
of catch basins and recorded levels on the order of several hundreds of enterococci per gram.
75
Table V.l:Results from enterococci and MST analysis for the 78 MST samples analyzed in this study inclusive of groundwater,PVC
water,and stormwater samples.All samples analyzed for human,dog,bird,and gull markers plus the general enterococci marker
(EnterolA).Boldcd results exceed the estimated risk-based threshold (RBT)of32 or 36 human illnesses per 1000 exposures for full
body_contact.See Section I.2.b for an explanation of the sources and assumptions made in the RBT values.
Enterococci General Human Specific Dog Specific General Bird Seagull Specific
Sample ID"Sample Type by culture Enterococcus "HF183 Taqman"DG3""GFD""Gull2"
MPN/100 "EnterolA"by Bacteroides qPCR Bacteroides Helicobacter spp.Catellicoccus
mL gPCR gc'I00mL gc/100mL gc/I00mL gc/I00mL gc/I00mL
F11-240723 Groundwater <10 128 ND"ND 629 ND
F1-240723 Groundwater 794 3,850 ND ND 93 ND
F3-240723 Groundwater 51 3,107 ND ND 811 ND
F2-240723 Groundwater <10 490 ND ND 139 ND
Fl0-240723 Groundwater 108 166 ND ND 412 ND
G8-240723 Groundwater 253 1,343 ND ND 298 ND
F9-240723 Groundwater 1,337 884 ND ND 93 ND
G17-240723 Groundwater 761 1,074 ND ND 74 ND
G10-240723 Groundwater <10 305 ND ND 93 ND
G16-240723 Groundwater 137 621 ND ND 204 ND
F4-240724 Groundwater <10 171 ND ND 233 ND
G5-240724 Groundwater <10 605 ND ND 878 ND
G4-240724 Groundwater <10 297 ND ND 175 ND
G13-240724 Groundwater 108 62 ND ND 89 ND
G11-240724 Groundwater <10 ISi ND ND 156 ND
G2-240724 Groundwater <10 355 ND ND 323 ND
G1-240724 Groundwater 228 4,853 ND ND 406 ND
G12-240724 Groundwater 85 4,419 ND ND 589 ND
F5-240725 Groundwater <10 1,354 ND ND 586 ND
R1-240725 Groundwater 10 394 ND ND 181 ND
R3-240725 Groundwater 97 2,478 ND ND 526 ND
F7-240725 Groundwater >24,196 30,387 ND ND 457 ND
F6-240725 Groundwater 216 1,707 ND ND 142 ND
G3-240725 Groundwater 145 569 ND ND 2,184 ND
G7-240725 Groundwater <10 93 ND ND DNQ (35)ND
R2-240725 Groundwater 10 DNQ 28)NQ 9)ND 206 ND
KS01-240815 PVC Surface 9,208 45,046 DNQ (13)ND 70,199%ND
KO01-240815 PVC I-ft Depth 457 3,757 DNQ (3)ND 189,793 ND
KF0l-240815 PVC 5-ft Depth 487 4,889 DNQ (18)ND 131,698 ND
KS07-240815 PVC Surface 373 2,798 ND ND 39,312 ND
KO07-240815 PVC 1-ft Depth 52 1,645 ND ND 23,903 ND
KF07-24081S PVC 5-ft Depth 529 11,502 DNQ (10)ND 108,482 ND
KS12-240815 PVC Surface 2,035 23,356 110 ND 58,014 ND
KO12-240815 PVC I-ft Depth 369 21,406 ND ND 110,437 ND
KF12-240815 PVC_5-f Depth 243 7,685 ND ND 60,479 ND
CS1-240805 PVC,BBE Outfall 17,329 8,218 ND ND 120 ND
CS2-240820 PVC,BBE Outfall 198,630 4,830 ND ND 1533 ND
CS3-240823 PVC,BBE Outfall 980 384,097 DNQ (6)1,197 52,361 ND
CS4-240823 PVC,BBE Outfall 740 255,555 DNQ (I)126 7,482 ND
CS5-240829 PVC,BBE Outfall 2,720 1,079,725 DNQ 21)149 25,886 ND
SRA2-240806 Stormwater 19,863 9,101 ND ND 93 ND
$RB6-240806 Stormwater 11,199 124,945 ND ND 853 ND
SRF5-240820 Stormwater 92,080 54,939 DNQ (24)ND 368 ND
BS14-240820 Stormwater 173,290 108,496 DNQ (26)ND 150 ND
SRN-240829 Stormwater 241,960 191,868 762 ND 1,026 6,192
SRK-240829 Stormwater 86,640 18,204 DNQ (5)ND 928 ND
SRL-240829 Storm water 61,310 13,094 DNQ (11)ND 149 ND
SRO-240829 Stormwater >241,960 1,308,273 DNQ (5)395 312 890
SRE8-240829 Stormwater 19,863 9,312 ND ND 122 ND
SRJ-240829 Stormwater 38 730 125 193 98 71 529 ND
76
Table V.l:continued
Enterococci General Human Specific Dog Specific General Bird Seagull Specific
Sample ID"Sample Type by culture Enterococcus "HF183 Taqman"DG3""GFD""Gull2"
MPN/100 "EnterolA"by Bacteroides qPCR Bacteroides Helicobacter spp.Catellicoccus
mL gPCR ge/I00mL ge/100mL ge/I0omL gce/I00mL gc/Io0mL
SRI-240829 Stormwater 11,590 14,157 DNQ (8)ND 163 ND
BS4-240806 Stormwater >24,196 2,429 ND ND 2,158 ND
SRC2-240806 Stormwater >24,196 134,149 DNQ (0.2)ND 299 ND
BS6-240806 Stormwater 443 95,549 DNQ(l7)121 77 ND
BS7-240809 Stormwater 11,199 552,321 ND ND 642 ND
SRD2-240809 Stormwater >24,196 1,633,586 ND ND 541 ND
BSl-240806 Stormwater >24,196 207,050 ND DNQ (1)934 ND
BS9-240809 Stormwater 19,863 837,129 DNQ (14)ND 111 ND
BS2-240806 Stormwater 24,196 1,106,920 297 165 2,212 ND
BSl0-240809 Stormwater 24,196 62,605 ND ND 229 ND
RSD-240725 Stormwater 14,136 2,272,419 ND ND 545 ND
RSF-240725 Stormwater >24,196 377,307 97 ND 244,327 ND
Pl-240805 Stormwater >24,196 842,109 ND 1137 696 ND
P3-240805 Stormwater 19,863 1,551,216 578 DNQ (46)745 ND
PSl-240806 Stormwater >24,196 3,893,670 338 270 1933 ND
PS3-240806 Stormwater 24,196 86,291 ND ND 950 DNQ (9)
BS 11-240809 Stormwater >24,196 54,733 ND ND 3,263 ND
BS13-240820 Stormwater 11,780 137,073 ND DNQ (D)331 ND
SRY-240910 Stormwater 104,620 1,926,120 ND ND 2,446 ND
SRH-240829 Stormwater >241,960 131,751 ND ND 571 ND
SRV-240910 Stormwater 241,960 669,747 ND ND 1,010 ND
SRZ-240910 Stormwater 155,310 3,482,500 ND ND 1,169 1274
BS3-240806 Stormwater 24,196 38,661 106 ND 21,773 ND
SRR-240910 Stormwater 198,630 716,107 ND ND 507 ND
SRU-240910 Stormwater 46,110 8,884,668 DNQ (16)5,322 4,114 ND
SRP-240829 Stormwater 77,010 536,051 900 79 533 ND
SRW-240910 Stormwater >241,960 6,914,729 ND ND 4,827 ND
Blank-240815 Blank <10 DNQQ)ND ND DNQ&)ND
Sample ID corresponds to the location (first 2 to 4 alphanumerics)and sample collection date (in YYMMDD format).
ND=Not Detected (below limit of detection).
DNQ="Detected but Not Quantified".These samples were detected at levels less than 50 gc/100 mL but could not be reliably or repeatably quantified
because they were below the environmental lower limit of quantification.The value in parenthesis next to DNQ is the estimated value of the qPCR
result.
'Bird Helicobacter "GFD"values and seagull "gull2"Catellicoccus values which do not meet the RBT just by themselves but are of sufficient level to
exceed the risk threshold when also combined with the level of human "HF! 83"marker in the sample,are also balded in this table. In addition,those
Human "HF 183"DNQ values in this table that might contribute synergistically to a combined human+bird fecal risk greater than 32 illnesses per I 000
exposures in a particular sample are also balded in this table to highlight their potential combined risk contribution.However,these DNQ values should
be viewed with some skeptical caution as these low DNQ values might also represent (at least in part)some background "noise"in the analysis since
they are below the eLLOQ.
77
Table V.2:Means (arithmetic and geometric)and medians for the 78 samples submitted for MST analysis.Values provided for enterococci and for
the MST markers (human,dog,bird,and gull).For computation purposes,samples measuring at detected but not quantifiable (DNQ)values were set
at the 50 gc/100 mL estimated detection limit.
Enterococci (MPN/IO0mL)Entero1A (gc/100mL)Human (gc/lO0mL)Dog (gc/IO0mL)Bird (gc/l00mL)Gull (gc/IO0mL)
Arith.Geo.Median Arith.Geo.Median Arith.Geo.Nedi Arith.Geo.Nedi Arith.Geo.N a;Arith. Geo-qa;
Mean Mean Mean Mean Mean Mean Iennan Mean M e tan Mean Mean 'en1an Mean Mean Hanean
Overall 38,136 2,318 11,199 532,972 20,046 18,204 137 33 ND 605 78 126 15,472 1,010 571 2,017 453 934
Groundwater 1,101 61 68 2,395 716 605 ND ND"ND ND ND ND 386 254 220 ND ND ND
Stormwater 72,262 37,693 24,196 1,057,418 232,197 191,868 194 59 50 634 57 100 8,152 765 642 2,017 453 934
PVC 16,72 5 1,262 635 132,465 18,837 9,860 27 11 12 491 282 149 62,836 27,317 55,188 ND ND ND
KL+BBE 29,002 3,842 2,378 225,453 43,312 34,201 30 11 13 491 282 149 31,863 11,460 32,599 ND ND ND
Surface
PVC KL 3,872 1,912 2,035 5,473 1,163 4,889 62 DNQ 62 ND ND ND 55,842 54,300 58,014 ND ND NDSurface
PVC KL 293 206 369 23,733 14,332 23,356 DNQ ND ND ND ND ND 108,044 79,424 110,437 ND ND ND1_foot
PVC KL 420 397 487 8,936 5,095 3,757 DNQ ND ND ND ND ND 100,220 95,246 108,482 ND ND ND5feet
PVC BBE 44,080 5,839 2,720 346,485 84,099 255,555 9 5 6 491 282 149 17,476 4,506 7,482 ND ND ND
Outfall
•DNQ=Detected but Not Quantified.These sam ples were detected at levels less than 50 gc/100 mL but could not be reliably quantified because they were below the lower limit of quantification.
ND =Not Detected (below limit of detection).
78
a)Overall levels for all samples b)Bird Marker Levels by Sample Type
10
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09
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10
Ground Storm
water water Canal Surface 1-foot 5-feet
Figure V.1:Box and whisker plot of enterococci (by culture and qPCR)and MST marker levels (bird,gull,
dog,and human).Overall levels (panel a)and levels of bird marker by sample type (panel b).For panel b,the
canal samples include those from the BBE Outfall.For panel b,the samples labeled,"surface","1-foot",and
"5-feet"correspond to the sites from the PVC at the Kayak launch.Red horizontal lines correspond to risk-
based thresholds.Two risk-based thresholds are shown for the bird markers,one for samples that show evidence
of human marker (22,500 gc/100 L)and another that shows no evidence of human marker (200,000 gc/100 L).
79
1o'
1o°
10
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Figure V.2:Results from enterococci (by culture and by EnterolA qPCR)and MST measurements for bird,
gull,human,and dog markers by sampling site.Data separated by sample type including groundwater (top
panel),stormwater (middle panel),and PVC water collected at BBE and at the Kayak Launch (bottompanel).
80
•Stormwater
@Groundwater
Pvc,surface
PVC,1-f oot
O PVC,5-foot
..,.....
oeooa ••
@
@
•@
#qr.go
•
....
@
•
9
0
Figure V.3:Spatial distribution of enterococei (Entero-lA)as measured by qPCR.
81
Legend
•Stormwater
@Groundwater t2.Pvc,surface @ •PVC,1-foot
0 PVC,5-foot ye X@·,xXx
....,)(xxx·,
.X x •.....,
X
%@ xi •·,x··••"
ix¥•
•
X
K I••.x ,....
p(X @ •x X ti iax
X
maX;j
x
X
x
•
Figure V.4:Spatial distribution of human MST marker.The "X"symbol represents samples below the
detection limit.
Legend
•Stormwater
@Groundwater .,,t::::-.:,@Pvc,surface •tar '«@
PVC,1-foot yX0PVC,5-foot @ X
X X ,1.~,·x
•••X
'~tX'°Xt,X ....
ye.
X
X\._X •••'K..
X '!
X 'I.X
X X
Xx
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,~
.X X
i<X
Xx
X
X
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')
X ....
Figure V.5:Spatial distribution of dog MST marker.The "X"symbol represents samples below the detection
limit.
82
•Stormwater
@Groundwater
@ Pvc,surface E
PVC,1-foot
O PVC,5-foot
0
•••
@
l
°e%
@
•
••
@0
••
Me Na••
9
@
•
Figure V.6:Spatial distribution of general bird MST marker.The "Y"symbol represents samples below the
detection limit.
•Stormwater 1
@Groundwater
Pvc,surface
O PVC,1-foot
O PVC,5-foot
tXx·
X
K
tao Xloe r•%X'X X Xfxik
X i X X t
I X?,X X tat,e
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X x·,...~·.,.,..X
):,,..,
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Figure V.7:Spatial distribution of gull MST marker.The "Y"symbol represents samples below the detection
limit.
83
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MST Marker SampleLabel
.
Distribution G:Groundwater
S:Storm
C:Canal
Human PVC:Kayak
Dog Launch
Bird
Figure V.8:Spatial distribution of human,dog and bird MST results emphasizing the relative amount of each
marker.Spatial distribution of pie charts shown for samples collected from groundwater (shown by G symbol),
stormwater (S),PVC at the BBE (C),and PVC at the Kayak Launch (PVC).Pie charts surrounded by a box
correspond to samples collected at the same location but during different times.
84
V.3 CORRELATIONS AMONG ENTEROCOCCI AND MST MEASUREMENTS
To evaluate whether associations exist between the enteroeoeei measurements (by culture and qPCR)and MST
measurements,correlations (Pearson's and Spearman 's)were evaluated.Details of the correlations analysis can
be observed in Figure V.9.Results show that enterococci by culture and by qPCR were significantly correlated
with Pearson's correlation coefficient,R,of0.31 (p<0.01)and with a Spearman's correlation coefficient,r,,of
0.79 (p<0.0001).Through the Pearson conelation,enterococci by qPCR was found to be correlated with the dog
marker (R=0.88,p<0.0001).Three additional Spearman correlations were found to be statistically significant
and included enterococei by culture and human marker (r=0.53,p<0.001),enterococei by culture and bird
marker (1,=0.25,p<0.01),enterococci by qPCR and dog marker (1,=0.64,p<0.01)and enterococci by qPCR and
bird marker (1,=0.38),p<0.001).
A correlation among the two methods of measuring enterococci is expected since they are both measuring
enterococei.The main difference is that enterococci by culture only measures live bacterial cells whereas
enterococci by qPCR measures the target gene copies of both live and inactive bacterial cells.Further focus on
the correlation and relationships between enterococei by culture and by qPCR is given in Figure V.I0 for an
arithmetic plot (panel a)and for a base-IO logarithmic conversion of the enterococi data (panel b).The
arithmetic plot is consistent with the Pearson's correlation analysis (R=0.31).The logarithmic transformation of
the enterococei which is common in the analysis of environmental fecal indicator bacteria data shows an
improvement in the correlation with a Pearson's R of 0.81.The high correlation confirms the consistency
among the different enterococei measurements.
a)Pearson b)Spearman
o to9o 400
ho.Enter0cocci
-0.1s #L
Lulu.,«by
0.31°0.36 0.05
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Figure V.9:Correlation plot betw een enterococci by culture and qPCR plus the MST markers (human,dog,and
bird)for the 78 samples analyzed for MST. Gull marker was not included clue to insufficient data points with
numerical values.Pearson correlation coefficients provided in panel a,and Spearman correlation coefficients
provided in panel b.Green shading indicates correlations that were statistically significant.Three stars indicate
p<0.0001,two stars indicate p<0.001,and one star indicates p<0.01.
85
a) Arithmetic Plot b)Log-10 Transformed Data Plot
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Enterococci by Culture (MPN/100 ml)Log(Enterococci by Culture)(MPN/100 mL)
Figure V.l 0:Enterococci by culture versus enterococci by qPCR for the 78 samples analyzed for Entero 1 A
marker,with an arithmetic plot (panel a)and Log-10 transformed data (panel b).
86
CHAPTER VI
OVERALL ASSESSMENT AND RECOMMENDATIONS
87
CHAPTER VI
O V E RA LL A SSESSMENT AND RECOMMENDATIONS
The recommendations below describe measures to reduce enterococci in stormwater at the street surface
(Section VI.1 ),in the groundwater (Section VI.2),within the stormwater conveyance system (Vl.3 ),within the
PVC (Section Vl.4)and to integrate treatment for fecal bacteria within long-term comprehensive stormwater
planning (Section VI.5).
VI.1 REDUCE ENTEROCOCCI IN STORMWATER AT STREET SURFACE
To reduce enterococci levels in stormwater we recommend the reduction of dog fecal waste (VI.1.a),reduce the
human fecal waste impacts to stormwater (VI.1.b ),make corrective actions to reduce enterococci from the BBE
outfall (VI.1.c),and reduce trash and rainwater in contact with trash (VI.l.d)
VI.1.a Reduce Dog Fecal Waste Impacts to Stormwater
We encourage the following tasks to help minimize dog fecal waste.
•Community Outreach.CMB public education efforts are commendable as evidenced by its easy-to-use
web site (https://www.miamibeachfl.gov/engagementtoolbox/),mobile apps used for communications
purposes,and signage to encourage dog owners to pick up pet waste.The CMB communicates the need
for dog owners to pick up after their dogs through publications in the CMB Newsletter,signage,doggie
bag/bin stations,and public outreach in English and Spanish.Dog friendly events,such as Yappy Hour,
held in October each year serve as opportunities for the CMB to encourage dog owners to pick up after
their dogs.
•Actively Enforce Dog Waste Disposal.CMB Code Compliance continues focusing on proactive
patrols while enforcing the cleanup of pet waste.These efforts should continue.
•Additional Dog Waste Stations.In addition to the numerous dog waste stations at Parkview Island
Park,during August 2024,the CMB added 5 additional dog waste stations throughout the catchment.
These new stations were installed at:74 Street &Carlyle NW Corner,74"&Harding Ave,73"&
Byron Park Side,7141 Dickens Ave,and 73"&Dickens SW Corner.Given the observation of dog
MST marker at 76"Street and Byron,we recommend an additional dog waste station at this location.
•Completion of the Dog Park.The CMB has plans for a dog park to include a vegetation buffer to
reduce dog waste from entering the canal.Currently,many dog owners walk their dogs through
Parkview Island Park along 72'Street and Dickens but the park is not currently designed to minimize
runoff of dog waste into the canal and storm drains.Completion of the dog park will help to properly
contain dog fecal waste.We recommend the park be designed to assure a first flush treatment of the
stormwater from the park.Upon the completion of the dog park,we recommend making extra efforts at
dog waste cleanup through frequent inspections and cleanup for dog waste sanitation.
•Reduce Other Animal Sources.Other sources of animal waste should be considered,such as waste
from iguanas,racoons,and other animals.The CMB has addressed other potential animal sources
through removal of animal feeding stations,signage to the public to not feed wildlife,and staff
monitoring of the Parkview Island Park and enforcement of park hours.Despite the signage and
enforcement to reduce feeding of wildlife,an animal feeding station (which attracted a flock of birds)
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was observed during a January 2025 visit to the PVC (See Figure C.18 in Appendix C).The CMB staff
have been aware of attempted continued efforts towards animal feeding stations which they
acknowledged have been difficult to police.Regardless,efforts should continue to eliminate animal
feeding stations and to reduce fecal waste from non-native wildlife.
•Continue with Aggressive Street Sweeping Activities.Through discussions with the superintendent of
sanitation for the CMB (Alvaro Rueda),we confirmed that street sweeping activities have increased.
There are two forms of street sweeping that involve the removal of solids which are disposed as solid
waste:mechanical and manual.Mechanical street sweeping frequency is 3 times per week throughout
the catchment.Manual street sweeping occurs 3 times per week on Parkview Island and 1 time per week
through the remainder of the catchment.Manual street sweeping is conducted on paved areas curbside
using a broom and dust pans (by the CMB litter crew).
•Consider Expanding Cleanup Activities.In addition to street sweeping,the CMB should consider
adding "poop scoopers"to manual clean-up efforts.The areas cleaned should include grassy areas where
visible dog waste is observed.Poop scoopers for grassy areas can include manual devices or devices that
can be dragged.
•Consider Disinfection.The CMB should also consider the possibility of technologies to disinfect grassy
areas and streets after the dog waste is picked up.UV disinfection devices are available for disinfecting
yoga mats and studio floors.We recommend applying these same devices to disinfect streets,and grassy
areas.The disadvantage of UV light is that it disinfects areas that are accessible to light only.Additional
liquid disinfectants should also be considered to penetrate areas not accessible by UV light.The
disadvantage of liquid disinfectants are chemical residuals that can impact ecosystems.Studies should
be considered to evaluate technologies for disinfection of grassy areas and streets.
VI.1.b Reduce Possibility of Human Fecal Waste Impacts to Stormwater
There is evidence that human fecal waste is contaminating stormwater.The source can come from direct
defecation or indirectly through sewer overflows.We therefore recommend the following to address this source.
•Conduct Study to Learn More About Homeless Populations.Data showed that human MST was
most predominant in the corridor connecting the parks located within Park View Island and the
southeast comer of the North Shore Park and Tennis Center.Additional human marker hot spots were
observed near parking lots in the center and northeast comer of the catchment.The movement and habits
of the homeless in this area should be investigated to better understand the need for sanitation facilities
in this area.The homeless in this area should be interviewed to ask about sanitation facility usage during
park hours and after hours.Attention should be given to identifying possible locations of encampments,
inclusive of the bridge at 73'Street.
•Access of Homeless Populations to Sanitation Facilities.Unlike the prior 2022 study,during the 2024
study the research team did not observe homeless encampments along the PVC.Since 2022,Parks &
Recreation continues their roaming patrols,and Environment &Sustainability staff alongside the Public
Works Operations team continue to work with Homeless Outreach on their increased routine site visits.
Efforts to relocate homeless living along the canal appear to be effective.However,homelessness was
observed during 2024 within the broader catchment area.These homeless populations do not have
access to sanitation facilities.The waste from these individuals will be carried by stormwater runoff
towards the PVC.We recommend that the CMB expand its efforts to provide access to sanitary
facilities.
•Conduct Study to Learn More About Usage of Existing Sanitation Facilities at Parks and at
Commercial Establishments.A study should be conducted about when and by whom the sanitation
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facilities are used at the parks.Additionally,workers at commercial establishments should be
interviewed about policies allowing non-staff workers usage of available sanitation facilities,especially
during non-park hours when public facilities may be closed.The workers at commercial establishments
should also be interviewed about the frequency with which non-staff request the use of the sanitation
facilities.This information will be helpful to determine whether access to public sanitation facilities
should be extended within the catchment.
•Increase Access of General Populations to Sanitation Facilities.Access is needed to sanitation
facilities.Populations visiting the area may have difficulties in finding facilities.In fact,it was common
for members of the research team to be denied access to bathroom facilities at commercial
establishments.Access to public facilities (e.g.,the Youth Center)is available only during Center hours.
•Avoid Sewage Backups through Sewage Water Level Monitoring.We recommend that the CMB
invest in technologies that can detect sewage backups.The CMB has evaluated the installation of
"smart"manholes fitted with water level recorders which can provide early warnings of sewage
backups.The reduction of sewage backups would minimize sewage spillage onto the streets which
ultimately enters the stormwater conveyance system.During May 2023,CMB Public Works installed
two SmartCover® devices in manholes in Parkview Island to monitor sewer levels to avoid sanitary
overflows.
•A void Sewage Backups through Grease Trap Enforcement.There are a total of 51 grease traps
documented in the catchment.Grease trap operations are inspected and monitored through the Building
Department the CMB through the FOG (Fats,Oils and Grease)program.Systems out of compliance are
notified to Miami-Dade County DERM for code enforcement.
•Disinfect Streets after Sewage Backups.When sewage backs up,it flows up through the manhole
covers,onto the street,and towards the stormwater system for drainage.In the process,the backed-up
sewage will contaminate the sediment on the streets providing for a sustained source of human fecal
contamination.The CMB has a Sanitary Sewer Overflow Response Plan (CMB 2022)which includes
immediate 24/7 emergency response through on-call staff.Clean up after the spill is to include removal
and/or decontamination of soil/plants and application of bleach or hypochlorite to disinfect surface areas
except in areas where it might be washed into surface waters.We recommend that the CMB consider
how to disinfect surface areas that may wash into surface waters.The disinfection should not result in
chemical residuals that may impact the ecosystem that receives the stormwater.The use of hydrogen
peroxide (degrades to oxygen and water),use of alcohol disinfectant sprays for small areas,and UV
light for surface disinfection should be considered.One advantage of liquids is that they can penetrate
areas that are not accessible by light.The advantage of UV light is that it does not cause a chemical
residual. Studies should be conducted to evaluate additional methods of disinfecting streets after sewage
backups.
VI.1.c Corrective Actions to Reduce Enterococci from the BBE Outfall
Given the distribution of the enterococci within storm water runoff and groundwater,we have identified the
BBE as a priority area for investigation for enterococci levels.Specifically,we recommend that:
•The CMB works with Miami Dade County Public Schools (MDCPS).The CMB should work with
MDCPS to inspect the BBE stormwater and sanitary systems to address the hotspot observed in
groundwater near the BBE and from the stormwater outfall from the MDCPS property.The CMB has
been in communication with representatives from the MDCPS Division of Safety and Emergency
Management and with the MDCPS Department of Regulatory Compliance.MDCPS have since
provided detailed plans about the sanitary and stormwater infrastructure on their site.They are working
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with the CMB to inspect areas which are high risk as potential enterococci sources.These high-risk
areas include three vertical stormwater wells on-site,a 6-inch cast iron gravity lateral pipe carrying
wastewater,a grease trap,and two stormwater conflict structures.One stormwater conflict structure
includes the 6-inch cast iron gravity lateral sewer line.The other stormwater conflict structure includes a
sanitary force main.Although these structures are designed to keep sanitary sewage separate from storm
water,they should be inspected to confirm no leakage.In addition to numerous meetings held virtually,
the staff from the CMB met with staff from MD CPS met in person at the BBE outfall site on January 31,
2025 to discuss plans for inspection and continued maintenance.MDCPS is required to maintain its
stormwater system as per County Class II permit,to avoid PVC water quality degradation.
VI.1.d Reduce Trash and Rainwater in Contact with Trash
Trash and rainwater in contact with trash (leachate)is a source of fecal indicator bacteria.Efforts should focus
on minimizing the amount of loose trash within the catchment and within the stormwater conveyance system
through the following approaches.
•Increase Frequency of Trash Pickup from Public Bins.Currently litter is picked up once a day from
public trash bins.No overflowing public trash bins were observed during this study.However,
depending upon the events within the area,pick up may need to be adjusted to avoid overflow of trash
bins.
•Assure that all Public Bins have Rain Domes.To avoid contact with rainwater,all public trash bins in
the area should be fitted with rain domes which are designed to eliminate rainfall from contacting the
trash.The CMB has since fitted public trash bins in the area with rain domes.
•Minimize Impacts from Commercial Trash Bins.Commercial trash bins should remain covered and
undisinfected washings from such bins should not enter the stormwater conveyance system.
•Encourage Homeowners to Keep Trash Bins Covered.The CMB has included messaging about
covering trash bins in its public outreach announcements including on the CMB website.(See
Community Updates at:https://www.mbrisingabove.com/climate-adaptation/biscayne-bay/park-view-
canal-water-quality/)
•Enhance Trash Pickup within Public Areas.Trash pickup should be included as part of street
sweeping and street cleaning initiatives.Although not much trash was observed on the streets,trash
should be picked up when seen from all public areas.
•Avoid Landscaping Trash in Catch Basins.Leaf blowers should not push gardening debris towards
the catch basins as this will clog the catch basins and contribute nutrients that will encourage the
persistence of fecal bacteria.
•Inspection of Catch Basins on a Regular Basis.Trash that is not picked up will be washed into the
stormwater catch basins.Catch basins should be inspected on a regular basis to remove trash for the
purpose of eliminating this source of bacterial contamination.Frequent trash removal from catch basins
has the added benefit of reducing flooding risks.
Targeted Public Outreach.Targeted public outreach is to continue towards commercial kitchens and
restaurants.They are to be informed not to use public streets and alleys to clean dumpsters,matts,and
equipment.This is considered littering of streets and illegal dumping into stormwater system as
contaminated cleaning water will drain into stormwater inlet.CMB Code Enforcement is to work with
business owners to confirm how dumpsters are managed.
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VI.2 REDUCE ENTEROCOCCI IN GROUNDWATER
Efforts should continue in inspecting and eliminating any potential leaks from the sanitary sewer system into
groundwater.Below are general recommendations (VI.2.a)and recommendations specific to the groundwater
hotspots found in this study (VI.2.b ).
VI.2.a General Recommendations to Reduce Enterococci in Groundwater
•Maintenance of Sanitary Force Main Air Release Valves.During the prior study,between January
and February 2023,force main air release valves were replaced or removed by the in-house CMB crews
due to observed leaks.Since then,the CMB has developed a Force Main Leak Detection Program led by
approved vendors and the CMB Public Works Engineering Division.The latest inspection,during
September 2024,included using acoustic/sonar technology to provide an added level of inspection.
During the September 2024 inspection,all air release valves,and force mains (21.5 miles inspected)
were intact and operating properly with no leaks (Utility Services Associates,2024).
•Additional Monitoring of Wastewater Force Mains for Pressure Drops.The CMB has a pressure
gauge system that is integrated into a SCADA (supervisory control and data acquisition)system.
Throughout the CMB,all lift stations are fitted with both digital and analog pressure gauges to detect
pressure drops which indicate potential leaks in the system.Additionally,field staff perform
preventative maintenance on all lift stations seven days a week.Maintenance includes ensuring that both
digital and analog pressure gauges are functioning as mandated.
•Continue with Aggressive Maintenance of Sewer Pump Stations.The CMB has prioritized North
Beach for aggressive sewer pump station maintenance.CMB Public Works has completed the
maintenance of sewer Pump Station no.21 during December 2021,Pump Station no.23 in February
2023,Pump Station no.19 in February 2024,and Pump Station no.22 during mid-2024.Additionally,
Pump Station no. 19 force main (discharge line) replacement is currently in the final permit phase with
construction to start February 2025.Pump Station no.22 force main replacement is under design and
permitting with construction to start mid-2025.
•Continue Sanitary Sewer Pipe Lining.The City completed more than $640K of Phase 1 Park View
Sewer Trenchless Rehabilitation upgrades and sewer force main air release valve replacements.The
Public Works Department completed pipelining to 95%of the gravity sanitary sewer pipes and 98%of
the manholes in Park View Island during fiscal year 2023.The rehabilitation of Pump Station No.23
wet well located on 75"Street adjacent to the PVC has been completed during the last quarter of 2024.
As part of Phase 2 North Beach and Park View Extended Area,more than $2.5 million of upgrades have
been set aside for improvements to the sanitary sewer system including lining 90%of the sewer lines
from 73""to 76 Street,rehabilitating manholes,rehabilitation of all North Beach the pump station wet
wells and planning for a force main replacement.As of mid-November 2025,all tasks associated with
the Phase 2 North Beach and Park View Extended Area project were completed except the wet well
rehabilitation of the sewer Pump Stations no.19 and 21.The wet well rehabilitation of Pump Station no.
19 (69 Street and Indian Creek)will be completed mid-December 2024 and Pump Station no.2I wet
well will be coordinated for the early 2025 dry season.
•Reduce Infiltration and Inflow into the Sanitary Sewer System.Reduction of infiltration and inflow
will help to maintain the capacity of the sewer and result in fewer backups due to limited capacity.The
CMB has been conducting work towards reducing infiltration and inflow into the sanitary sewer system
(Hazen 2022a).The focus has been on rehabilitating manholes,gravity mains,and laterals.Techniques
utilized include night flow isolation,camera inspections (CCTV),manhole inspections,and smoke
testing.A study specific to Parkview island (Hazen 2022b)found multiple gravity sewer pipes in need
of cleaning and repair.These pipes have been repaired by lining the sewers to reduce leaks.This study
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focused on gravity sewers within the public right-of-way and did not evaluate the integrity of sewer
laterals on private property.
•Continue Searching for Sanitary Sewer Leaks.The CMB has conducted considerable work towards
identifying potential sewage leaks.Work should continue in sanitary sewer inspections and stormwater
conveyance system inspections,especially those that evaluate the potential cross connections between
the sanitary sewer and storm conveyance system.Techniques used by the CMB include evaluation of the
proximity of the systems through GIS and evaluation of construction drawings,dye testing,camera
inspection (CCTV),acoustical testing,and smoke testing.
•Continue Water Sampling Efforts.Sampling and water quality analysis is conducted routinely by the
CMB.Additionally,the CMB has contracted special studies to identify sources of contamination.These
include a contract with ESciences which sampled the catch basins,and with Source Molecular for the
analysis of source tracking markers.They have also contracted two studies through the University of
Miami including this current one which includes source tracking.
VI.2.a Location Specific Recommendations to Reduce Enterococci in Groundwater
Groundwater measurements showed the highest hot spot close to the BBE.The next highest spots were along
72nd Street.Recommendations for how to address each hot spot are as follows:
•Address the hot spot at the BBE through cooperation with Miami Dade County Public Schools
(MDCPS).Additional details in Section VI.1.c above.
•Address hot spot in the middle of the parking lot between 72'and 73"Street between Harding
and Collins.This hot spot is located within an area of intense underground wastewater infrastructure
with the capacity of moving wastewater to a historic outfall that extended into the bay at 74 Street.This
infrastructure is old and in need of replacement.The new proposed community center for this area (72%
Street Community Complex)includes plans for an Olympic-sized roof-top swimming pool,a warm-up
pool,library and media center,community room,fitness gym with running track,greenspace,and multi-
level parking.The construction of the complex will result in the removal of the historic wastewater
infrastructure within the existing parking lot through the creation of a bypass around the complex along
Harding Avenue.If the complex is constructed,the sewage system will be completely replaced.In terms
of the timeline,30%of the design plans,with a cost estimate,were submitted at the end of October
2024.The application to the design review board will likely happen early 2025.The construction budget
is estimated at $70M,and it will likely be funded by a General Obligation Bond.
•Additional hotspots were observed in groundwater along 73"%Street at Wayne Street and at
Dickens Avenue.These sites are near sites where human MST marker was observed in the stormwater.
It is possible that stormwater is contaminating the groundwater at these locations.This specific area
should be further studied to evaluate the movement and habits of homeless populations in this area,with
frequent inspections of the area under the bridge at 73""Street for possible homeless encampments.The
search for possible sanitary sewage contamination should also continue in this area.
VI.3 REDUCE ENTEROCOCCI WITHIN THE STORMWATER CONVEYANCE SYSTEM
The catchment contributing towards the PVC is highly urbanized with a significant amount of impervious area
with disproportionately small areas available for natural treatment or attenuation of contaminants carried by
runoff.Due to this situation,the catchment is unable to naturally cleanse itself and will rely on human
intervention or actions to reduce levels of enterococci in runoff that is carried towards the PVC.Below are
recommendations for actions that can be taken to reduce enterococci through improvements to the stormwater
conveyance system.
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•Evaluate Approaches to Increase Pervious Areas.Common ways to treat the first flush involve
letting the first portion of the rainfall-runoff enter a detention area where particulates settle.Other
designs are based upon the use of grassy swales to retain the first flush.Given the lack of space for
stormwater retention,consideration should be provided towards replacing impervious areas with
pervious systems,such as pervious concrete,that allow for runoff treatment.
•Treat the Stormwater First Flush through a Short-term Solution.The CMB has plans to add
hydrodynamic separators to the stormwater conveyance system as a means of reducing the sediments
discharged into the PVC.A notice to proceed has been issued,and a kickoff meeting was held
September 2024.The permit will be submitted to DERM during February to March 2025.A two
hundred-thousand-dollar budget has been allocated for the design and permitting support.The CMB has
allocated $2M in its capital plan.The scope of services includes retrofits to seven of the major
stormwater outfalls that flow directly into the PVC.The completion target date for this work is 2026.
•Treat the Stormwater First Flush through a Long-term Solution.The CMB was awarded a $1 OM
Florida Resilient Grant for the design and permitting of a Neighborhood Improvement Project (North
Shore D Neighborhood Improvement Project).This includes a proposed stormwater conveyance system
that will replace the existing stormwater pipe network from 69"Street to the south to 73""Street to the
north and from the PVC to the west to Collins Avenue to the east.The stormwater conveyance system is
currently projected to include new catch basin structures,manhole structures,conveyance piping,
injection wells (to treat the first flush),and up to two stormwater pump stations.The stormwater pump
stations will be configured to include upstream water quality filtration and treatment to treat the first
flush of contaminants in the form of bar racks,vortex water quality structures,and up flow stormwater
quality cartridge filters.Additionally,energy dissipation structures will be constructed downstream of
the pump stations prior to discharge into adjacent canals to prevent damage to the existing plant life and
canal bottom.The stormwater system will also be fitted with back flow prevention devices to prevent
backflow of tidal waters into the stormwater system.The scope of this project also includes the
replacement of adjacent potable water and sanitary sewer conveyance,distribution,and transmission
systems.The aerial potable water and sanitary sewer pipe crossings at the 71 st street bridge immediately
south of the PVC will be replaced with subaqueous crossings under the scope of this project.The CMB
is applying for additional grants and completing a rate study to secure construction funding.The CMB is
working towards a completion target date of 2028.More details about this project is available at:
https://www.miamibeachfl.gov/residents/neighborhood-affairs-division/active-projects/neighborhood-
improvements/north-shore-d-phase-one/
•Remove Illicit Connections.Illicit connections are those that are not composed of stormwater or
composed of stormwater from private property.Private property is to retain its own rainwater.Illicit can
also flow during dry weather due to connections with other sources of water and examples can include
water from car washing,clothes washing,and inadvertent cross connections with sanitary sewage.The
CMB is currently working with the legal authority (County/DERM) on illicit discharges from outfalls.A
list of illicit connections from private storm systems to public sewer systems is provided biannually to
DERM and CMB continues to actively notify the environmental regulatory authorities.Connections
prior to 1984 (when DERM was established)have been grandfathered.It is our understanding that these
grandfathered connections can only be legally addressed when the facility with the connection goes
through its 40-year recertification.In the meantime,the CMB will continue to refer these connections to
DERM and will press the county for a resolution.
•Private property stormwater system best management and maintenance practices.Private property
owner shall hold Class II permits with Miami-Dade County and use best management and maintenance
practices to avoid further degradation of the PVC.
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VI.4 REDUCE ENTEROCOCCI WITHIN THE PVC
In addition to limiting inputs of enterococci through runoff and possible sanitary sewer leaks,efforts should also
focus on improving the conditions of the PVC to facilitate the reductions of enterococci once received by the
waterway.Efforts to reduce enterococci internal to the PVC are as follows:
•Dredging of the PVC.The purpose of dredging is to improve flushing and remove sediment and marine
debris.The CMB has committed about $500,000 in designed fees for canal-based restoration/dredging
efforts (contract to TYLin with hydrographic/bathymetric survey by M.G.Vera and Associates).The
project is currently in the design phase.The bid documents for this project should be available by
January 2026 with project mobilization by June 2026 and completion by January 2027.The cost for
design and permitting is $500K.The dredging is estimated at $2 million.
•Improve Shorelines.To limit the erosion of sediments and transport of trash by runoff along the
shoreline,we recommend protecting the shoreline by increasing vegetation cover,inclusive of
mangroves and other plant species,which act as deterrents to the public accessing the PVC.To address
this issue,the CMB acquired Cummins Cederberg to conduct a Nature Based Shoreline Assessment
(CCI 2021)that selected the most viable locations for living shorelines within the sites of CMB-owned
seawalls.Ten locations were identified,two of which are directly adjacent to the PVC.The Cummins
Cederberg study showed that the 2,460-foot shoreline along the PVC is densely packed with mangroves.
The living shoreline project will remove invasive vegetation,repair and rehabilitate damaged seawalls,
and mitigate coastline erosion.The CMB had applied for an earlier grant through the NOAA
Transformational Habitat Restoration and Coastal Resilience Grants program.This earlier application
was not awarded.The CMB,however,has since received a federal appropriation agreement for $963K
which will be used towards the Design of the North Beach Living Shorelines Project which is to include
the PVC plus Bayside Lane and 6860 Indian Creek Drive.These funds will be used to acquire
engineering and design professional services to complete coastal and civil engineering analysis,
preparation of plans and specifications,plan formulations,engineering calculations,and other necessary
studies.
•Conduct Bird Study Focused on the Channel Banks and Fecal Waste Throughout the Catchment.
The MST results support that a major cause of elevated enterococci in the PVC is due to birds.A study
is recommended to document the number and type of birds,which nest and forage along its banks,that
contribute directly to the waterway.The mitigation measures for the birds will depend upon the type of
birds found and through an understanding of what is attracting the birds to the area.In addition to
concentrating efforts within the PVC,a study should be conducted throughout the catchment.Of interest
would be to inspect roof tops for evidence of bird nests and waste,perhaps using drones.If nesting birds
are found on roofs,bird deterrents should be considered in efforts to minimize contamination of roof
runoff by bird fecal waste.If migratory birds are found to be the likely contributor,of interest would be
to conduct sample analyses over different seasons to determine possible relationships with bird
migratory patterns.In addition,efforts are to continue to eliminate illicit bird feeding stations which
have been observed to continue (despite enforcement)within the watershed.
•Continue with Water Quality Monitoring.The CMB regularly monitors the PVC at the Kayak
Launch site for fecal bacteria (enterococci and fecal coliform)monthly, inclusive of measurements of
nutrients (Total Phosphorus,Nitrogen as Nitrate+Nitrite,Kjeldahl Nitrogen and Ammonia)and basic
physical-chemical parameters (water temperature,pH,dissolved oxygen,salinity,and specific
conductivity).Miami Surfrider is also monitoring the PVC for enterococci at the same site on a weekly
basis.The CMB has also contracted with consultants and the University of Miami to conduct intense
sampling programs aimed at identifying the source of elevated bacteria.
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VI.5 LONG-TERM COMPREHENSIVE STORMWATER PLANNING
Long-term comprehensive stormwater planning should include the integration of methods to treat for fecal
indicator bacteria.The most recent comprehensive long-term stormwater and sanitary sewer plans that address
water quality are listed below.
•Stormwater Master Plan.The CMB had initiated through its Stormwater Master Plan Update and
Capital Improvement Plan a critical needs analysis to be addressed by the City over 10 years.The plan
has taken several criteria into consideration including stormwater flooding,tidal flooding,water quality
issues,and resident complaints.The Stormwater Master Plan was presented to City Commission in
November of 2023 and approved by the City Commission on March 2024 (
https://www.miamibeachfl.gov/wp-content/uploads/2024/03/Miami-Beach-Prioritizes-95-Million-in-
Infrastructure-Improvements.pdf).The Master Plan prioritizes 20 projects ($95M)in infrastructure
improvements.Within the 20 recommended critical needs projects two projects (North Shore B&C at
Dickens Ave ranked 9 and North Shore at Byron Avenue ranked 11)are listed.Among the five on-
going water quality projects,one of the major outfalls to the PVC is ranked 3.Among the 14
neighborhood improvement projects,North Shore D &Town Center Improvements is ranked 5.Plan
details are available at:https://www.mbrisingabove.com/wp-
content/uploads/March_13_2024_CMB_Commission_Presentation_S WMP-1.pdf.
96
VI.6 SUMMARY AND RECOMMENDATIONS
The PVC is a waterway that is restricted in terms of its flow.It is a canal located within a canal located in north
Biscayne Bay which suffers from poor water quality.The PVC receives stormwater from a large area (81.3
acres)and thus,contaminants tend to remain within the waterway and are not flushed readily from the system.
Superimposed on the limited dilution capacity is an outdated stormwater infrastructure that was not designed to
retain the first flush of contaminants.
In response,the CMB greatly increased the intensity of efforts to control enterococci sources between August
2022 and February 2023.Improvements in water quality were statistically significant when separating the data
between before and after these time periods.We also observed a decrease in baseline levels of enterococci
between storm events from thousands ofMPN/100 mL during 2022 to hundreds of MPN/100 mL during 2024.
Of particular significance is the reversal in the trend between storms where during 2024,the highest enterococci
levels were observed during high tide,suggesting that groundwater may no longer serve as a primary source of
enterococci.Although measurements made during 2024 show improvements in water quality,the levels of
enterococci observed in the PVC are still elevated beyond levels considered safe for swimming and for
kayaking.
Results from the current study which aimed to identify sources of enterococci within the watershed found very
high levels of enterococci within stormwater collected at street level.The highest levels of enterococci in
stormwater coincided with quantifiable levels of dog and human fecal waste.Birds were found to be a
significant contributor within the PVC.We made several recommendations for the CMB to further work on
identifying and eliminating bird,dog,and human waste.Among these three sources,human waste is most
concerning given that it was detected in stormwater suggesting the intermittent presence of human waste within
the streets.We therefore recommend studies to better understand sanitary facility needs in the area for homeless
populations and others who visit the catchment.Once the needs are known,mitigation strategies can be
implemented to reduce and/or meet the need.
In the long term,improving the circulation of the PVC (through dredging)and the installation of stormwater
treatment processes that include trash racks,sediment vortexers,and beyond would be the most impactful.
These improvements,however,require considerable investments and time for design,permitting and
construction.In the short term,the CMB should continue its aggressive education and outreach efforts to dog
owners,homeless populations,commercial establishments,and the community at large to minimize enterococci
contributions on an individual level.Additionally,the CMB should maintain its high frequency of street
sweeping and trash collection.We recommend that the CMB go a step further and consider "deep cleaning"
which would include dedicated clean-up of visible waste from grassy areas and consideration of disinfection of
street surfaces and grassy areas especially after sewage spills.Given that bird fecal waste markers were
observed throughout the catchment and especially within the PVC,efforts are needed to better understand the
types of birds within the area and what may be attracting them.Once known,mitigation measures can be
determined for addressing bird fecal waste.In addition to addressing potential sources of bird,dog,and direct
human waste,the CMB should continue its aggressive efforts at monitoring and maintaining the sanitary sewer
system to minimize the possibility of impacts from leaks.In addition to continued inspections and lining of the
sanitary sewer system,the revamping of the sanitary sewer mains that are part of the proposed 72"Street
Community Complex would also be of benefit by providing a sanitary sewer system that is more robust and less
susceptible to leaks.The City should continue to work closely with MDCPS to confirm that the school's
stormwater conveyance and sanitary sewer systems are intact and operating as originally designed.
97
ACKN OWLEDGMENTS
This project was funded by the City of Miami Beach.We thank the City of Miami Beach Public Works and the
Department of Environment and Sustainability who provided available data and logistical support during
sampling efforts.The Capital Improvement Project Office participated and provided feedback during meetings.
We also thank the many interested parties who have shared their insights with us during our time out in the field
and during meetings within the City to better understand the cause of the elevated enterococci levels.We also
extend our gratitude to Miami Surfrider who shared their data and met with the team to describe their efforts
within the watershed.We are also grateful to M.G.Vera and Associates and TYLin for facilitating the
benchmark at the Kayak Launch.
98
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102
APPENDICES
103
APPENDIX A
HISTORICAL DATA
(CMB AND SURFRIDER)
104
Table A.l:Concentration of enterococci in samples collected monthly by the CMB from PVC Kayak Launch from 4/17/2019 to 9/30/2024 with fecal coliform and
other physical chemical parameters recorded including nitrogen (Nitrate+Nitrite,Ammonia,Kjeldahl),total phosphorus, salinity,water temperature,pH,dissolved
oxygen,turbidity,and cumulative precipitation (6-hour,12-hour,24-hour,48-hour)at station WS3 with S27 _Ras back up.When S27_R is used as the backup,the
font color is blue.Data also includes confirmed water elevation at NOAA Virginia Key Station (Bear Cut),estimated water level at the PVC,tide cycle,and
groundwater elevations at the PVP within the shallow,intermediate,and deep wells.All elevations are in units of feet NAVD88.
Fecal Nitrogen (mg/L)Dissolved Precipitation (in)Water Level (ft)Groundwater elevation (ft)Enterococci Total WaterColiformsSalinity Turbidity Tide Cycle atDateTime(MPN/100 Phosphorus Temp pH Oxygen
ml)(CFU/100 NO,+NO,Ammonia Kjeldahl (mg/L)(psu)C)(mg/L)(NTU)6-hour/12-hour24-hour48-hour Bear Cut PVC PVC shallow inter.deepmL)
4/17/2019 11:10AM 640 125 <0.025 <0.035 <0.089 0.040 28.2 27.7 7.95 5.20 7.50 0.00 0.00 0.00 0.01 -0.95 -0.72 EBB -0.63 -0.67 1.75
5/20/2019 11:03AM 63 25 <0.025 0.042 0.21 0.042 27.4 29.9 8.02 5.36 N/A 0.00 0.00 0.00 0.00 0.38 -0.34 EBB -0.01 0.07 2.49
6/27/2019 10:56AM 169 400 0.029 <0.035 0.34 0.036 20.8 30.8 8.03 6.95 1.28 0.00 0.00 0.00 0.00 -1.45 -1.38 EBB -0.06 -0.01 2.40
7/29/2019 11:51AM 1660 402 0.044 <0.035 0.27 0.034 15.8 30.9 8.04 7.05 2.66 0.00 0.00 0.00 0.01 -1.09 -0.90 EBB 0.22 0.28 2.64
8/13/2019 11:58AM 934 92 0.072 <0.035 <0.086 0.038 15.8 32.8 7.99 5.21 3.29 0.00 0.00 0.22 1.02 -0.49 -0.24 EBB 0.10 0.11 2.50
9/25/2019 11:10AM 285 157 <0.025 0.04 0.31 0.044 25.2 29.4 7.85 4.63 2.92 0.00 0.00 0.00 0.00 -0.7 -0.43 EBB 0.59 0.61 3.02
10/16/2019 9:26AM 359 430 <0.025 <0.035 0.33 0.058 20.1 28.0 8.10 4.60 3.60 0.00 0.00 0.00 0.00 1.19 -1.32 FLOOD 0.79 0.82 3.29
11/19/2019 11:10AM 108 20 <0.033 <0.035 0.18 0.032 15.8 23.7 7.72 7.32 3.78 0.00 0.00 0.00 0.00 1.02 -1.06 FLOOD 2.40 1.53 3.94
12/23/2019 10:19AM >24196 600 0.17 <0.035 0.23 0.059 10.8 22.3 7.89 5.79 9.43 0.01 6.01 6.01 6.01 -0.55 -0.29 EBB 0.25 0.27 2.63
1/15/2020 11:15AM 73 270 <0.033 <0.035 0.290 0.040 17.9 24.9 7.84 5.10 6.24 0.00 0.00 0.00 0.03 -0.080 -0.19 FLOOD -0.61 -0.55 1.92
2/3/2020 11:22AM 679 112 0.14 0.12 0.350 0.042 22.6 21.9 7.77 6.19 2.53 0.00 0.00 0.00 0.37 -0.960 -1.20 FLOOD -0.12 -0.05 2.35
3/17/2020 10:36AM 331 260 <0.033 <0.0317 0.330 0.055 36.0 25.0 8.11 4.87 16.40 0.00 0.00 0.00 0.00 -1.490 -1.43 EBB -0.20 -0.12 2.29
4/14/2020 10:06AM 142 92 <0.033 <0.035 0.290 0.044 36.3 28.0 8.06 6.67 6.44 0.00 0.00 0.00 0.00 -1.720 -1.95 FLOOD -0.37 -0.29 2.14
5/26/2020 10:23 AM 13000 so 0.21 0.079 0.370 0.040 14.4 26.1 7.78 5.85 4.36 0.03 0.18 3.88 6.30 0.320 -0.23 FLOOD 0.37 0.39 2.87
6/23/2020 10:38AM 20 so <0.033 <0.035 0.290 0.027 27.2 30.2 8.25 6.63 1.92 0.00 0.00 0.01 0.04 0.380 -0.27 FLOOD -0.73 -0.68 1.79
7/29/2020 10:40AM 283 340 <0.033 <0.035 0.270 0.034 28.0 31.2 8.30 5.26 4.66 0.00 0.00 0.00 0.00 -1.850 -1.77 EBB -0.22 -0.16 2.28
8/14/2020 11:15AM 437 570 <0.033 0.054 0.254 0.056 29.3 31.9 7.95 3.88 4.46 0.00 0.01 0.02 0.04 -1.270 -1.15 EBB -0.08 -0.01 2.42
9/22/2020 10:55 AM 1010 1320 <0.033 0.049 0.390 0.034 30.2 29.9 7.98 4.23 8.14 0.00 0.00 0.78 1.07 1.030 -1.08 FLOOD 1.14 1.21 3.69
10/13/2020 10:47 AM 19900 600 0.066 0.06 0.280 0.028 23.7 29.5 7.88 4.30 1.33 0.00 0.00 0.40 0.44 -0.650 -0.38 EBB 0.41 0.42 2.87
11/18/2020 10:37 AM 1560 142 0.085 <0.035 0.290 0.033 26.0 26.3 8.02 5.74 2.80 0.00 0.00 0.00 0.00 1.250 -1.40 FLOOD 0.23 0.27 2.78
12/21/2020 11:15AM 959 96 0.036 <0.035 0.310 0.055 31.8 23.1 8.15 5.69 1.60 0.00 0.00 0.00 0.00 -0.220 -0.27 FLOOD 0.18 0.26 2.73
1/28/2021 10:48AM 1090 110 <0.033 0.052 0.370 0.041 32.9 23.6 7.87 5.97 2.07 0.00 0.00 0.00 0.00 -0.460 -0.22 EBB N/A -1.06 1.50
3/29/2021 11:05AM 161 145 <0.033 <0.035 0.360 0.031 36.8 27.4 8.21 4.30 9.58 0.00 0.00 0.00 0.00 0.510 -0.47 EBB N/A -1.08 1.49
4/30/2021 11:02AM 173 20 <0.033 <0.035 0.310 0.023 36.2 28.1 8.29 5.72 3.18 0.00 0.00 0.00 0.00 0.080 -0.16 FLOOD N/A -0.70 1.87
5/25/2021 10:55AM 323 114 <0.033 <0.035 0.170 0.029 36.3 N/A 8.15 6.81 6.38 0.00 0.00 0.00 0.00 -0.590 -0.32 EBB N/A N/A N/A
6/16/2021 10:41AM 6590 600 N/A N/A N/A N/A 28.5 28.0 7.97 3.45 3.80 0.00 0.07 1.27 1.54 -0.840 -1.03 FLOOD N/A N/A N/A
7/14/2021 11:00AM 487 300 0.088 0.07 0.320 0.030 28.8 26.3 7.97 3.71 6.00 0.00 0.06 0.73 5.46 -0.380 -0.41 FLOOD N/A N/A N/A
8/16/2021 10:47AM 1510 2100 0.11 0.044 N/A N/A 26.3 29.6 8.02 4.48 5.49 0.00 0.00 0.04 0.41 -1.570 -1.89 FLOOD N/A N/A N/A
9/22/2021 11:50AM 17300 N/A 0.065 <0.035 0.270 0.022 26.2 30.2 7.93 5.55 8.56 0.91 0.91 1.14 1.14 0.750 -0.76 EBB N/A -0.25 3.05
10/28/2021 10:29AM 521 670 0.027 <0.035 0.340 0.007 29.6 27.9 7.81 3.80 2.09 0.00 0.00 0.00 0.00 -0.74 -0.88 FLOOD N/A -0.53 2.76
11/15/2021 10:45AM 2140 770 0.044 <0.035 0.460 0.011 29.4 24.2 7.05 7.10 4.11 0.00 0.00 0.00 0.00 -0.58 -0.31 EBB N/A 0.08 3.36
12/22/2021 10:26AM 1660 440 0.018 0.040 0.300 0.011 33.1 21.4 7.72 5.01 7.80 0.00 0.00 0.09 0.13 0.72 -0.63 FLOOD N/A -0.05 3.21
"N/A=Not Available
105
Table A.I (Continued)
Fecal Nitrogen (mg/L)Precipitation (in)Water Level (ft)Groundwater elevation (ft)
Enterococci Coliforms Total Salinity Water Dissolved TurbidityDateTime(MPN/100 Phosphorus Temp pH Oxygen Tide Cycle at
ml){CFU/100 NO,+NO,Ammonia Kjeldahl (mg/L)(psu)(°C)(mg/L)(NTU)6-hour 12-hour 24-hour 48-hour Bear Cut PVC PVC shallow inter.deepmL)
1/18/2022 11:30AM 211 58 0.024 <0.035 N/A 0.010 32.4 20.6 8.06 6.33 2.07 0.00 0.00 0.00 0.24 -0.09 -0.10 EBB N/A -0.23 3.03
2/25/2022 10:28AM 1310 38 <0.015 <0.035 0.250 0.010 34 25.5 7.92 3.25 4.49 0.00 0.00 0.00 0.00 -1.42 -1.74 BOTTOM_UP N/A N/A N/A
3/30/2022 10:48AM 187 82 <0.015N/0.54 0.29 0.011 35.4 24.8 8.03 6.06 8.16 0.00 0.00 0.00 0.00 -0.89 -0.64 EBB N/A N/A N/A
4/25/2022 10:17AM 504 114 <0.015 <0.035 N/A 0.009 38.1 26.5 8.14 6.54 5.76 0.00 0.00 0.00 0.00 -1.07 -0.88 EBB N/A N/A N/A
5/19/2022 10:37AM 173 147 <0.015 <0.035 0.300 0.007 37.2 29.4 8.14 4.59 5.37 0.00 0.00 0.00 0.00 0.26 -0.20 FLOOD N/A N/A N/A
6/14/2022 10:38AM 399 430 N/A N/A 0.280 0.008 25 30.8 8.05 2.71 0.21 0.01 0.01 0.01 0.01 0.36 -0.32 EBB N/A N/A N/A
7/18/2022 10:53AM 30 20 0.027 <0.035 0.370 0.013 34.6 29.2 10.48 3.13 8.25 0.00 0.00 0.00 0.10 -0.53 -0.58 FLOOD N/A N/A 2.84
8/11/2022 10:54AM 41 62 N/A N/A 0.410 0.011 35.5 27.9 7.26 5.38 19.80 0.00 0.00 0.00 0.00 -0.06 -0.10 EBB N/A N/A 2.41
09/15/2022 11:09AM 909 28 0.038 0.045 0.410 0.018 31.1 26.7 7.59 5.78 6.17 0.00 0.00 1.67 2.03 0.48 -0.36 FLOOD N/A N/A 3.79
10/17/2022 10:48AM 278 184 0.030 N/A 0.420 0.011 29.9 28.5 8.17 7.43 4.19 0.00 0.00 0.01 0.14 -0.14 -0.22 FLOOD N/A N/A N/A
11/17/2022 11:07:00 >24196 640 0.062 0.056 0.49 0.021 28.5 23.6 7.59 5.06 6.14 0 0 0 0 -0.41 -0.44 FLOOD N/A N/A N/A
12/12/2022 10:52:00 109 10 0.046 0.036 0.45 0.010 33 25.5 8.38 4.87 2.71 0 0 0 0 0.98 -1.00 FLOOD N/A N/A N/A
1/20/2023 11:15:00 84 155 N/A N/A 0.26 0.0080 35.2 23.2 6.78 7.02 3.97 0 0 0 0 -0.95 -0.72 EBB N/A -0.76 N/A
2/17/2023 8:13:00 41 24 N/A N/A 0.33 0.0092 N/A 23.9 7.24 8.53 6.71 0.03 0.03 0.03 0.03 -0.18 -0.10 EBB N/A N/A N/A
3/14/2023 11:07:00 52 70 0.028 N/A 0.32 0.0078 36.1 22.4 8.13 8.17 1.36 0 0 0 0 -0.13 -0.21 FLOOD N/A N/A N/A
4/26/2023 10:33:00 652 240 0.052 <0.035 0.33 0.0094 24.2 26.8 8.02 5.61 1.04 0 0.03 0.03 0.21 -0.68 -0.79 FLOOD N/A N/A N/A
5/16/2023 11:10:00 20 380 N/A N/A 0.31 0.0062 33.3 22.4 8.36 8.23 0.77 0 0 0.01 0.17 -1.02 -0.81 EBB N/A N/A N/A
6/13/2023 11:11:00 108 240 N/A N/A 0.28 0.0047 28.9 21.5 7.87 1.87 0.76 0 0 0.46 0.46 -1.35 -1.25 EBB N/A N/A N/A
7/18/2023 10:43:00 292 360 0.032 0.064 0.36 0.0083 27.6 20.9 8.2 8.17 0.63 0 0 0.05 0.16 0.25 -0.20 FLOOD N/A N/A N/A
8/24/2023 11:15:00 30 40 0.017 <0.035 <0.14 0.013 31.6 31.4 8.11 2.62 12.9 0 0 0 0 -0.6 -0.68 FLOOD N/A N/A N/A
9/21/2023 10:40:00 196 N/A 0.031 0.058 0.40 0.011 28.3 29.9 7.19 4.67 1.59 0 0 0.11 0.49 -0.27 -0.31 FLOOD N/A 0.14 N/A
10/17/2023 11:22:00 20 66 0.038 0.078 0.40 0.011 30.2 26.7 8.06 3.7 11.2 0 0 0 0 1.33 -1.51 FLOOD N/A 0.39 N/A
11/22/2023 10:13:00 10 50 0.061 0.11 0.38 0.0083 28.9 24.7 8.06 6.74 2.3 0 0 0 0 -0.91 -0.63 BOTTOM_DOWN N/A -0.44 N/A
1/4/2024 1:00:00 288 72 0.027 0.13 0.34 0.0078 31.2 20.9 8.02 7.01 7.77 0 0 0 0 -0.5 -0.55 FLOOD N/A N/A N/A
1/17/2024 10:46:00 1440 292 0.024 0.10 0.35 0.0090 32.3 23.6 7.42 4.69 5.36 0 0 0 0 -0.68 -0.79 FLOOD N/A N/A N/A
2/16/2024 10:56.00 175 112 0.018 0.092 N/A 0.012 35.4 23.8 7.67 4.21 5.79 0 0 0 0 -0.87 -1.07 FLOOD N/A N/A N/A
3/12/2024 10:24.00 301 184 N/A 0.05 0.67 0.014 34.8 25.9 7.53 3.95 12.5 0 0 0 0 0.35 -0.25 FLOOD N/A -0.38 N/A
4/10/2024 10:55:00 122 29 0.018 N/A 0.34 0.0095 35.2 25.2 7.61 3.51 4.08 0 0 0 0 0.91 -0.90 FLOOD N/A N/A N/A
5/14/2024 10:27:00 241 27 0.015N/0.035 0.26 0.0040 36.4 29.7 7.8 4.41 3.18 0 0 0 0 -0.86 -1.06 FLOOD -0.34 -0.75 2.78
6/18/2024 11:01:00 3430 N/A 0.071 N/A 0.42 0.020 23 29.5 7.77 5.47 2.98 0 0 0.09 1.15 -O.68 -0.41 EBB N/A -0.69 N/A
7/17/2024 10:55:00 326 142 N/A N/A 0.32 0.017 32.5 32.3 7.43 2.54 6 0.06 0.06 0.06 0.15 -1.3 -1.19 EBB -0.86 -1.34 2.24
8/15/2024 10:28:00 259 125 N/A N/A 0.31 0.014 32 32.9 7.78 2.89 3.71 0 0 0 0 -1.51 -1.45 EBB -1.12 N/A 2.69
9/19/2024 11:43:00 683 485 0.038 0.039 0.40 0.014 27.4 30.8 7.78 2.18 2.1 0 0.01 0.27 0.31 0.34 -0.25 FLOOD 1.04 0.64 4.20
106
Table A.2:Concentration of enterococci in samples collected monthly by Surfrider from the PVC Kayak Launch from
10/14/2021 to 9/30/2024 with water temperature and cumulative precipitation (6-hour,12-hour,24-hour,48-hour)at
station WS3 with S27_R as back up.When S27_R is used as the backup,the font color is blue.Data also includes
confirmed water elevation at NOAA Virginia Key Station (Bear Cut),estimated water level at the PVC,tide cycle,and
groundwater elevations at the PVP within the shallow,intermediate,and deep wells.All elevations are in units offeet
NAVD88.
Precipitation (in)Water Level (ft)Groundwater elevation (ft)
Enterococci Water Tide Cycle atDateTime(MPN/100 Temp 48-PVCml)("C)6-hour 12-hour 24-hour hour Bear Cut PVC shallow inter.deep
10/14/2021 9:00:00 218 29.4 0 0 0 0 -0.59 -0.32 EBB N/A -0.71 2.61
10/21/2021 9:00:00 73 28.9 0 0 0 0 0.79 -0.73 FLOOD N/A 0.26 3.47
11/4/2021 12:40:00 <10 28.3 0 0 0 0 -0.18 -0.10 EBB N/A -0.66 2.69
11/11/2021 10:00:00 235 26.1 0 0 0 0 -0.16 -0.23 FLOOD N/A -0.11 3.20
11/18/2021 3:25:00 1019 25.0 0.05 0.05 0.05 0.05 -0.86 -1.16 BOTTOM_UP N/A -0.63 2.73
12/2/2021 8:30:00 1576 26.1 0 0 0 0 0.83 -0.86 EBB N/A 0.21 3.46
12/9/2021 3:20:00 684 25.0 0 0 0 0 0.11 -0.15 EBB N/A -0.24 3.05
12/16/2021 3:05:00 896 26.1 0 0 0 0.22 -0.83 -1.01 FLOOD N/A -0.88 2.45
12/23/2021 10:00:00 120 25.0 0 0 0 0.09 0.26 -0.20 FLOOD N/A -0.25 3.00
12/30/2021 12:45:00 <10 25.0 0 0 0 0 -1.3 -1.64 BOTTOM_UP N/A -1.06 2.29
1/13/2022 4:10:00 122 25.6 0.01 0.02 0.06 0.82 0.55 -0.43 FLOOD N/A -0.08 3.21
1/20/2022 4:15:00 537 25.0 0 0.28 0.28 0.28 -1.32 -1.16 BOTTOM_DOWN N/A -1.08 2.24
1/27/2022 3:00:00 110 23.9 0 0 0 0 0.35 -0.25 FLOOD N/A -0.22 3.08
2/3/2022 3:05:00 160 23.9 0 0 0 0 -0.96 -0.73 EBB N/A -0.58 2.77
2/10/2022 3:16:00 146 23.9 0 0 0 0.1 0.28 -0.21 FLOOD N/A -0.33 2.93
2/17/2022 2:00:00 538 22.8 0 0.01 0.08 0.08 -0.95 -0.72 EBB N/A -0.71 2.64
2/24/2022 2:15:00 122 24.4 0 0 0 0 0.12 -0.16 FLOOD N/A N/A N/A
3/3/2022 12:30:00 275 24.4 0 0.01 0.04 0.16 -0.35 -0.16 EBB N/A N/A N/A
3/10/2022 2:55:00 226 25.6 0 0 0 0 -0.08 -0.10 EBB N/A N/A N/A
3/17/2022 11:00:00 110 26.1 0.01 0.01 0.01 0.04 0.28 -0.25 EBB N/A N/A N/A
3/24/2022 10:00:00 243 26.1 0 0 0 0 -1.11 -1.42 FLOOD N/A N/A N/A
3/31/2022 11:00:00 345 24.4 0 0 0 0 0.28 -0.25 EBB N/A N/A N/A
4/7/2022 9:00:00 41 23.9 0 0 0 0 -1.04 -1.38 BOTTOM_UP N/A N/A N/A
4/14/2022 12:25:00 548 23.9 0 0 0 0 -1.06 -0.86 EBB N/A N/A N/A
4/21/2022 2:20.00 98 23.9 0 0.01 0.1 0.1 0.68 -0.67 EBB N/A N/A N/A
4/28/2022 12:20:00 75 25.6 0 0 0 0 -1.16 -1.00 EBB N/A N/A N/A
5/5/2022 11:15:00 1679 25.0 0 0 0.04 0.04 -0.25 -0.29 FLOOD N/A N/A N/A
5/12/2022 10:20:00 327 24.4 0 0 0 0 0.21 -0.20 EBB N/A N/A N/A
5/19/2022 11:40:00 63 27.8 0 0 0 0 0.73 -0.64 FLOOD N/A N/A N/A
5/26/2022 9:30:00 243 26.7 0 0 0 0 -0.31 -0.14 EBB N/A N/A N/A
6/2/2022 12:30:00 336 28.3 0.01 0.01 0.14 0.18 0.35 -0.31 EBB N/A N/A N/A
6/5/2022 8:35:00 3282 27.8 0 0.05 0.89 10.21 -0.95 -1.28 BOTTOM_UP N/A N/A N/A
6/9/2022 11:30:00 4352 25.6 0 0 0.45 0.48 -1.33 -1.18 BOTTOM DOWN N/A N/A N/A
6/16/2022 10:46:00 216 27.2 0 0 0 0 0.7 -0.60 FLOOD N/A N/A N/A
6/23/2022 11:00:00 51 27.2 0 0 0 0.45 -1.09 -0.84 BOTTOM_DOWN N/A N/A 2.50
6/30/2022 11:00:00 30 30.0 0 0 0 0 0.17 -0.18 EBB N/A N/A 2.69
7/7/2022 11:40:00 >24196 30.0 0 0 0 0.27 -1.26 -1.61 FLOOD N/A N/A 2.53
7/14/2022 11:00:00 63 30.0 0 0.07 0.07 0.07 0.48 -0.43 EBB N/A N/A 2.59
7/21/2022 1:00:00 20 30.0 0 0 0 0 -0.85 -1.04 FLOOD N/A N/A 2.72
7/28/2022 1:00:00 345 30.0 0 0 0 0.67 -0.87 -0.62 EBB N/A N/A 2.03
N/A=Not Available
107
Table A.2:(continued)
Precipitation (in)Water Level (ft)Groundwater elevation (ft)
Enterococci Water Tide Cycle atDateTime(MPN/100 Temp 48-mL)("C)6-hour 12-hour 24-hour Bear Cut PVC PVC shallow inter.deephour
8/4/2022 1:40:00 142 30.0 0.29 0.29 0.29 0.29 0.43 -0.31 FLOOD N/A N/A 3.06
8/11/2022 1:45:00 1169 30.0 0 0 0 0 -1.61 -1.56 EBB N/A N/A 1.88
8/18/2022 1:45:00 294 30.0 0 0 0.25 0.25 0.5 -0.38 FLOOD N/A N/A 3.30
8/25/2022 12:50:00 288 30.0 0 0 0 0 -1.05 -0.85 EBB N/A N/A 2.15
9/1/2022 12:30:00 20 29.4 0 0 0 0 0.4 -0.29 FLOOD N/A N/A 3.17
9/8/2022 8:30:00 1576 30.0 0 0.01 0.01 0.01 1.06 -1.17 EBB N/A N/A 3.24
9/15/2022 8:45:00 24150 29.4 0.03 0.06 2.09 3.08 -0.61 -0.69 FLOOD N/A N/A 3.35
9/22/2022 7:00:00 >24196 30.0 0.12 0.12 0.12 0.96 0.99 -1.02 FLOOD N/A N/A 3.79
9/30/2022 1:45:00 134 23.9 0 0 0 0.22 1.33 -1.50 EBB N/A N/A 3.64
10/6/2022 2:30:00 173 28.3 0 0 0 0 -0.41 -0.44 FLOOD N/A N/A 3.39
10/13/2022 8:30:00 617 26.7 0 0.02 0.02 0.02 0.12 -0.16 FLOOD N/A N/A N/A
10/20/2022 8:00:00 2359 26.7 0 0 0.59 0.63 0.37 -0.33 EBB N/A N/A N/A
10/27/2022 12:15.00 214 26.7 0 0 0 0 1.44 -1.62 EBB N/A N/A N/A
11/3/2022 12:25:00 324 27.2 0 0.05 0.05 0.05 -0.69 -0.94 BOTTOM_UP N/A N/A N/A
11/12/2022 9:30:00 21430 27.8 0 0 0.01 0.05 0.73 -0.64 FLOOD N/A N/A N/A
11/17/2022 12:55:00 106 27.2 0 0 0 0 0.17 -0.17 FLOOD N/A N/A N/A
11/25/2022 11:30:00 243 25.6 0 0 0 0.01 1 -1.09 EBB N/A N/A N/A
12/1/2022 9:30:00 109 25.0 0 0 0.08 0.08 -0.97 -0.70 BOTTOM DOWN N/A N/A N/A
12/8/2022 9:15:00 823 25.0 0 0 0.1 0.1 0.81 -0.75 FLOOD N/A N/A N/A
12/15/2022 3:05:00 63 23.9 0 0 0 0.34 0.76 -0.77 EBB N/A N/A N/A
12/22/2022 8:50:00 350 22.8 0 0 0 0.2 1.41 -1.59 EBB N/A N/A N/A
12/29/2022 11:45.00 1989 23.9 0 0 0 0.16 0.05 -0.16 FLOOD N/A N/A N/A
1/5/2023 1:30:00 987 23.9 0 0 0 0 -1.44 -1.37 EBB N/A -1.13 N/A
1/12/2023 8:30:00 480 23.9 0 0 0 0 -0.74 -0.88 FLOOD N/A -1.03 N/A
1/19/2023 2:00:00 414 21.1 0 0 0 0 -1.17 -1.52 BOTTOM_UP N/A -1.04 N/A
1/26/2023 2:40:00 85 23.3 0 0 0 0.02 -0.24 -0.12 EBB N/A N/A N/A
2/2/2023 2:00:00 446 23.3 0 0 0 0 -1.14 -1.49 BOTTOM_UP N/A N/A N/A
2/9/2023 11:00:00 41 23.3 0 0 0 0.01 0.54 -0.42 FLOOD N/A -0.29 N/A
2/16/2023 1:15:00 323 25.0 0 0 0 0 -1.12 -1.43 FLOOD N/A N/A N/A
2/23/2023 2:30:00 <10 25.0 0 0 0 0 -1.14 -0.97 EBB N/A N/A N/A
3/2/2023 11:00:00 52 23.3 0 0 0 0 -1.06 -0.86 EBB N/A N/A N/A
3/9/2023 9:30:00 160 N/A 0 0 0 0 0.79 -0.73 FLOOD N/A -0.26 N/A
3/16/2023 12:00:00 31 21.1 0 0 0.01 0.01 -0.62 -0.84 BOTTOM_UP N/A -0.42 N/A
3/23/2023 12:40:00 <10 N/A 0 0 0 0 0.37 -0.33 EBB N/A N/A N/A
3/30/2023 1:00:00 4352 N/A 0.07 0.07 0.36 0.86 -0.9 -1.12 FLOOD N/A -0.82 N/A
4/6/2023 8:00:00 295 N/A 0 0 0 0 -0.07 -0.19 FLOOD N/A -0.36 N/A
4/13/2023 12:45:00 626 N/A 0.01 0.01 1.16 3.03 0.3 -0.22 FLOOD N/A 0.43 N/A
4/20/2023 8:40:00 426 N/A 0 0 0 0 0.73 -0.64 FLOOD N/A 0.07 N/A
4/27/2023 12:30:00 1028 N/A 0 0 2.01 2.04 -0.26 -0.30 FLOOD N/A N/A N/A
108
Table A.2:(continued)
Precipitation (in)Water Level (ft)Groundwater elevation (ft)
Enterococci Water Tide Cycle atDateTime(MPN/100 Temp 48-PVCmL)(C)6-hour 12-hour 24-hour hour Bear Cut PVC shallow inter.deep
5/11/2023 10:00:00 63 N/A 0 0 0 0.04 -1.03 -1.31 FLOOD N/A N/A N/A
5/18/2023 11:00:00 359 N/A 0 0 0.14 0.18 -0.15 -0.10 EBB N/A N/A N/A
5/25/2023 12:35:00 166 N/A 0 0 0.11 0.84 0.39 -0.28 FLOOD N/A N/A N/A
6/1/2023 12:00:00 487 N/A 0 0 0.01 1.20 -0.81 -0.55 EBB N/A N/A N/A
6/8/2023 9:00:00 >24196 28.3 0 0 0.22 0.51 -0.47 -0.51 FLOOD N/A N/A N/A
6/15/2023 1:00:00 598 28.9 0 0 0 0 -1.49 -1.43 EBB N/A N/A N/A
6/22/2023 12:40:00 1067 28.3 0.05 0.05 0.05 0.84 0.25 -0.20 FLOOD N/A N/A N/A
6/29/2023 12:30:00 199 29.4 0 0.01 0.01 0.01 -1.38 -1.70 BOTTOM_UP N/A N/A N/A
7/6/2023 9:00:00 140 30.0 0 0 0 0 -0.65 -0.75 FLOOD N/A N/A N/A
7/14/2023 12:28:00 135 30.6 0 0.05 0.05 0.05 -1.32 -1.21 EBB N/A N/A N/A
7/20/2023 1:00:00 122 30.6 0 0 0 0 -0.17 -0.10 EBB N/A N/A N/A
7/27/2023 12:15:00 2924 32.2 0 0.14 0.33 0.45 -1.58 -1.85 BOTTOM_UP N/A N/A N/A
8/3/2023 12:15.00 41 30.6 0 0 0 1.46 0.75 -0.76 EBB N/A N/A N/A
8/10/2023 10:30:00 428 30.0 0 0 0 0 -1.68 -1.79 BOTTOM_DOWN N/A N/A N/A
8/17/2023 12:30:00 520 29.4 0 0.01 0.48 0.52 0.04 -0.12 EBB N/A N/A N/A
8/24/2023 9:00:00 52 27.2 0 0 0 0 -1.02 -0.76 BOTTOM_DOWN N/A -0.76 N/A
8/31/2023 12:30:00 677 28.9 0.02 0.09 0.09 0.28 -0.19 -0.11 EBB N/A -0.85 N/A
9/7/2023 12:30:00 31 30.0 0 0 0 0 -0.46 -0.50 FLOOD N/A N/A N/A
9/14/2023 12:30:00 <10 31.1 0 0 0 0 -0.13 -0.10 EBB N/A N/A N/A
9/21/2023 12:00:00 345 30.0 0.01 0.01 0.12 0.5 0.22 -0.19 FLOOD N/A 0.17 N/A
9/28/2023 8:30:00 1421 27.2 0.06 0.09 0.18 2.92 1.79 -1.86 EBB N/A 0.67 N/A
10/5/2023 8:50:.00 4884 26.7 0 0 0.08 0.08 -0.35 -0.41 BOTTOM_UP N/A 0.09 N/A
10/12/2023 7:00:00 473 27.2 0 0 0.24 0.24 1.18 -1.30 FLOOD N/A 0.54 N/A
10/19/2023 11:30:00 1082 27.2 0 0 0 0 0.98 -1.00 FLOOD N/A 0.41 N/A
10/26/2023 11:30:00 63 27.8 0.02 0.03 0.2 0.2 0.13 -0.16 EBB N/A -0.20 N/A
11/2/2023 11:50:00 >24196 27.8 0 0.08 0.57 0.57 1.18 -1.30 FLOOD N/A 0.64 N/A
11/9/2023 2:20:00 1173 26.7 0 0 0 0.01 0.3 -0.22 FLOOD N/A -0.02 N/A
11/16/2023 2:00:00 24196 27.2 0 0.3 6.7 8.35 0.7 -0.69 EBB N/A 1.05 N/A
11/22/2023 1:00:00 63 25.0 0 0 0 0.01 -0.18 -0.24 FLOOD N/A -0.31 N/A
12/7/2023 1:00:00 1223 26.1 0 0 0 0 -0.3 -0.33 FLOOD N/A -0.56 N/A
12/14/2023 1:00:00 1223 26.1 0.03 0.05 0.13 0.48 0.12 -0.15 EBB N/A -0.15 N/A
12/21/2023 2:00:00 865 25.6 0 0 0 0 0.41 -0.30 FLOOD N/A -0.13 N/A
12/28/2023 3:00:00 >24196 23.3 0.54 0.56 0.56 0.60 -1.22 -1.02 BOTTOM_DOWN N/A -0.73 N/A
1/4/2024 1:00:00 173 23.9 0 0 0 0 0.04 -0.16 FLOOD N/A N/A N/A
1/11/2024 2:15:00 3968 22.8 0.02 0.09 0.19 0.28 -1.5 -1.46 BOTTOM_DOWN N/A N/A N/A
1/18/2024 2:00:00 30 25.0 0.01 0.01 0.01 0.04 0.28 -0.21 FLOOD N/A N/A N/A
1/25/2024 10:00:00 98 21.7 0 0 0 0 0.11 -0.15 EBB N/A N/A N/A
2/1/2024 9:.00:.00 1565 25.0 0 0 0 0 -0.79 -0.95 FLOOD N/A N/A N/A
2/8/2024 9:00:00 591 21.1 0 0 0.01 0.01 1.04 -1.14 EBB N/A N/A N/A
2/15/2024 10:00:00 199 23.9 0 0 0 0.01 -0.89 -1.10 FLOOD N/A N/A N/A
2/22/2024 1:30:00 246 23.9 0 0 0.01 0.01 -1.14 -0.91 BOTTOM_DOWN N/A N/A N/A
2/29/2024 12:00:00 84 22.8 0 0 0 0 -0.15 -0.22 FLOOD -0.26 N/A 2.82
109
Table A.2:(continued)
Precipitation (in)Water Level (ft)Groundwater elevation (ft)
Enterococci Water Tide Cycle atDateTime(MPN/100 Temp 48-PVCmL)(c)6-hour 12-hour 24-hour hour Bear Cut PVC shallow inter.deep
3/7/2024 1:30:00 24196 23.3 0.01 0.27 0.31 0.93 -1.33 -1.66 BOTTOM_UP N/A N/A N/A
3/14/2024 11:00:00 73 22.8 0 0 0 0 -0.21 -0.26 FLOOD N/A -0.54 N/A
3/21/2024 12:00:00 441 25.6 0 0 0 0.01 -0.85 -0.60 EBB N/A N/A N/A
3/28/2024 7:00:00 323 25.6 0 0 0 0 -0.74 -0.88 FLOOD N/A -0.39 N/A
4/4/2024 12:30:00 11199 25.0 0.03 0.65 0.65 0.65 -1.53 -1.82 BOTTOM_UP N/A -1.08 N/A
4/11/2024 1:00:00 86 22.8 0 0 0 0 0.48 -0.43 EBB N/A -0.65 N/A
4/18/2024 1:00:00 41 25.6 0 0 0 0 -1.25 -1.59 BOTTOM_UP N/A -1.03 N/A
4/25/2024 9:30:00 146 26.1 0 0 0 0 0.25 -0.20 FLOOD 0.03 -0.34 3.14
5/2/2024 8:00:00 404 23.9 0 0 0 0.01 -0.62 -0.35 EBB N/A -1.08 N/A
5/9/2024 10:00:00 323 25.6 0 0 0 0 0.69 -0.59 FLOOD N/A -0.20 N/A
5/16/2024 8:30:00 185 28.9 0 0 0 0 -0.78 -0.51 EBB N/A -1.06 N/A
5/23/2024 12:15:00 20 28.9 0 0 0 0.25 -0.01 -0.11 EBB -0.20 -0.64 2.91
6/6/2024 1:00:00 <10 26.7 0 0 0 0 -0.71 -0.44 EBB N/A -1.04 N/A
6/13/2024 10:00:00 24196 26.7 0.01 0.14 10.68 16.43 -1.22 -1.56 BOTTOM_UP N/A N/A N/A
6/20/2024 1:00:00 1296 28.3 0.01 0.03 0.03 0.05 -1.16 -1.00 EBB N/A -1.09 N/A
6/27/2024 12:00:00 2359 28.3 0 0 1.28 1.97 -0.06 -0.18 FLOOD 0.25 N/A N/A
7/5/2024 2:45:00 10 30.0 0 0 0 0 -1.4 -1.29 BOTTOM_DOWN -0.77 -1.23 2.31
7/11/2024 10:00:00 122 32.2 0 0 0.06 0.06 -0.61 -0.69 FLOOD -0.36 N/A 2.73
7/18/2024 12:00:00 10462 32.2 0 0 0 0.06 -1.56 -1.51 EBB -0.99 -1.45 2.13
7/25/2024 12:00:00 146 28.3 0 0 0 0 0.41 -0.30 FLOOD 0.07 -0.32 3.18
8/1/2024 1:00:00 905 28.3 0.01 0.01 0.01 0.06 -1.76 -1.95 BOTTOM_DOWN -1.16 -1.61 1.92
8/8/2024 10:00:00 341 27.8 0 0 0 0.13 -0.35 -0.38 FLOOD -0.37 N/A 2.69
8/15/2024 12:00:00 12997 28.9 0 0 0 0 -1.75 -1.93 BOTTOM_DOWN -1.23 N/A 1.87
8/22/2024 8:00:00 3300 30.0 0 0 0.21 0.58 -1.11 -1.42 FLOOD N/A -1.08 2.44
8/29/2024 12:00:00 473 30.0 0 0 0 0.01 -1.13 -0.96 EBB -0.63 N/A 2.48
9/5/2024 4:00:00 830 27.8 0 0 0 0.03 0.54 -0.50 EBB -0.53 -0.98 2.58
9/12/2024 4:30.00 6488 28.3 0.55 0.55 1.08 3.14 -0.87 -1.07 FLOOD 0.67 0.09 3.81
9/19/2024 12:00:00 1850 30.6 0 0.01 0.27 0.31 0.78 -0.71 FLOOD 1.04 0.64 4.20
9/27/2024 1:00:00 10466 30.6 0 0 0.07 0.17 -0.81 -0.55 EBB 0.05 N/A 3.12
110
APPENDIXB
STORMWATER INFRASTRUCTURE DETAIL
111
APPENDIXB
STORMWATER INFRA STRUCTURE DETAIL
The stormwater infrastructure was evaluated to document the elevations in reference to groundwater and PVC
water levels.The elevations were documented through 1)data available through the CMB GIS system,b)
available construction drawings,and 3)for components that did not have elevations measurements,through
surveying that was initiated by CMB Public Works Department to measure inverts of outfalls to the PVC.
Details of these three approaches are described below.
B.1 GIS MEASUREMENTS
The CMB has a GIS system that documents the stormwater conveyance
and sanitary sewer infrastructure.The legend for the stormwater
information stored in the CMB GIS system (Figure B.1)documents the
locations of catch basins,culverts,trench drains,French drains,etc.In
some cases,the dimensions and elevations of the storm water conveyance
system are listed.For the stormwater conveyance lines that have
elevation data,that data was recorded and used to document elevations.
B.2 CONSTRUCTION DRAWINGS
The CMB made available construction drawings for both stormwater
conveyance and sanitary sewer system.For lines that lacked stormwater
conveyance system drawings,the sanitary sewer system drawings were
used to obtain elevations as the stormwater conveyance infrastructure
was shown on sanitary sewer drawings.A map of the catchment area
with the construction drawings available was constructed to confirm
coverage.Some details obtained from the construction drawings are
provided in Figures B.2 to B.6.Areas that did not have elevation
information by either GIS or constructions drawings were then surveyed
by the CMB.
B.3 SURVEYING OF OUTFALLS
Visible outfalls discharging to the PVC were surveyed by CMB Public
Works on November 4,2024.All elevations are referenced to NAVD88.
The results from this surveying exercise are shown in Figure B.8.
Drawing Order
r,.,Map3
athbasin
Overtlow
Sandard
Standard Mahle
rd Drain
O ther
a¢storm Gr avity Main
Maus line
co Culvert
as }yteral lir e
Bubble Up tine
henh [rain
a fr@nch Dain
a (Oetlow (ine
andored
5st ormn 24196
Store(anal 2419(0
t rm+anal 24 19
t 241960 Map Proportional
4 24 19 6 0 Gra duate d
I ¢K£241960 Graduated
¢KO 2 41960 Graduated
I's KS2419460 Graduated
Gro und 2419460_Grad uated
112
Figure B.1:Example ofLegend
of the CMB Stormwater GIS
Figure B.2:Storm conveyance construction drawings at 75 Street.
74th St
HE--
·H
ICi)4
~,I1
#
H#
Figure B.3:Storm Conveyance Constrnction Drawings at 74 Street.
113
Figure B.4:Sanitary Sewer Construction Drawings at 73 Street.
114
Figure B.5:Surface Elevation Map and GIS Image at 73 Street between Dickens and Abbott Avenue.Surface
Elevation Map from CES Consultants Survey February 2024 for the North Shore D North Beach TowCenter
Neighborhood Improvement Project.
\\13rd St
Figure B.6:Surface Elevation Map and GIS Image at 73 Street and Collins Avenue.Surface Elevation Map
from CES Consultants Survey February 2024 for the North Shore D North Beach Town Center Neighborhood
Improvement Project.
115
24'8 Cw--4
i
hob
8'
I MALI
PLAN VIEW
CE:NT.5.
Cx ¢SEA.
wtH CUN.HEYE
SECTION 4
CE;.TS.€r c»
Figure B.7:Detail for BBE Outfall Structure.Floor of vertical well chamber =0.00 ft.Overflow to second
well,invert 0.50 ft.Bypass from wet well to canal,invert at 0.00 ft.
116
aerofootElevSeawall:2.5isl{it..,
MD:4.30
Inv Outfall:·1.72
--~----4----....,.L!._.::'•::..;:•»•-J,(
\
J -
v Seawall.6.o&.
MD:7.44
Inv Outtalt:-1.46'
Figure B.8:Results from field survey for outfalls to the PVC.
117
APPENDIXC
UM SAMPLE COLLECTION TIMELINE
AND DATA DETAILS
118
APPENDIXC
UM SAMPLE COLLECTION TIMELINE AND DATA DETAILS
Table C.1:Sample Collection Timeline
Date Location Activities
6/18/2024 •Walk through from Parkview Island to Walkway on Scouting visit to identify groundwater
north end of PVC inclusive of the sanitary sewer pump drilling sites and possible stormwater
station collection sites
•Walk through the Parkview Island Park and Kayak
Launch
•Walk through tennis center area inclusive of
groundwater well sites
•Drive through entire watershed up and down streets and
avenues
7/15-• Throughout watershed Confirming sites for groundwater
19/2024 sampling including white-lining drill
areas and confirming underground utility
markings.
7/22/2024 •Throughout watershed Ground penetrating radar of all 3 1
proposed groundwater sampling sites.
7/23/2024 •Groundwater on south side of watershed including Groundwater sample collection (n=10)
Parkview Island.Sites Fl 1,Fl,F3,F2,Fl 0,G8,F9,
G17,G10,Gl6
7/24/2024 •Groundwater on east side and central portion of Groundwater sample collection (n=8)
watershed.Sites F4,G5,G4,Gl3,Gll,G2,Gl,G12
7/25/2024 •Groundwater on north side of watershed.Sites F5,Rl,Groundwater sample collection (n=8)
R3,F7,F6,G3,G7,R2
July 25,•Site RSD.Southeast comer of the private parking lot at Stormwater sample collection from
2024 the corner of 74 and Harding.Parking lot next to a puddles (n=3)
CVS.
•Site RSE.Storm drain at the intersection of74th and
Dickens.On the east side of Dickens Ave
•Site RSF.East side of comer of76th and Dickens.
August 5,•Puddle sites Pl,P3,P4,P5,P6 Stormwater sample collection from
2024 •Canal site CS 1 puddles (n=5)
(Day 1 Canal sample at outflow by school
targeted
stormwater)
August 6,•Puddle sites PS 1,PS3,PS7,PS8,PS9 Stormwater sample collection from
2024 •Field-staged bottle sites BSl,BS2,BS3,BS4,BS6 puddles (n=5)
(Day 2 •In person stormwater sample collection site SRA.Stormwater sample collection from field-
targeted Samples collected included SRA-2,SRA-3,and SRA-4.staged bottles (n=5)
stormwater)•In person stormwater sample collection site SRB.In person stormwater sampling at catch
Samples collected included SRB-1,SRB-2, SRB-3,basins at three different locations (n =3 +
SRB-4,SRB-5,SRB-6,SRB-7, SRB-8 3 +8 =14 total)
•In person storrnwater sample collection site SRC.
Samples collected included SRC-1,SRC-2,SRC-3
119
Table C.l 1 continued):Sample Collection Timeline
Date Location Activities
August 9,•Puddle sites PSl0,PS11,PS12,PS13,PS14,PS15 Stormwater sample collection from
2024 •Field-staged bottle sites BS7,BS8,BS9,BSl0,BS 11,puddles (n=6)
(Day 3 BS12 Stormwater sample collection from field-
targeted •In person stormwater sample collection site SRD.staged bottles (n=6)
stormwater)Samples collected included SRD-I,SRD-2,SRD-3,In person stormwater sampling at catch
SRD-4,SRD-5,SRD-6,SRD-7,SRD-8 basins at two different locations (n =8 +
•In person stormwater sample collection site SRE.8 =16 total)
Samples collected included SRE-1,SRE-2,SRE-3,SRE-
4,SRE-5,SRE-6,SRE-7,SED-8
August 15,•Sample collection at the PVC Kayak Launch at the Sample collection at the PVC kayak
2024 water's surface,KS0l,KS02,KS03,KS04,KS05,KS06,launch at three different water depths on
KS07,KS08,KS09,KSlO,KSll,KS12 an hourly basis from 6 am to 5 pm
•Sample collection at the PVC Kayak Launch at one-foot (n=35).
depth,KO0l,KO02,KO03,KO04,KOOS,KO06,Processing of the field blank (n=l)
KO07,KOOS,KO09,KOI0,KOl l,KO12 Sample collection ofrainwater (n=l)
•Sample collection at the PVC Kayak Launch at five-foot
depth,KF0l,KF02,KF03,KF05,KF06,KF07,KF08,
KF09,KFl0,KFll,KF12
•Field blank and rainwater collected at the Kayak Launch
August 20,•Puddle sites PSIS,PSI 7,PS18,PS19,PS20,PS21,Stormwater sample collection from
2024 PS22,PS23,PS24 puddles (n=l0)
(Day4 •Field-staged bottle sites BS13,BS14 Stormwater sample collection from field-
targeted •In person stormwater sample collection site SRF.staged bottles (n=2)
stormwater)Samples collected included SRF-1,SRF-2,SRF-3,SRF-In person stormwater sampling at catch
4,SRF-5,SRF-6,SRF-7,SRF-8 basin (n=8)
•Canal site CS2 Canal sample at outflow by school (n=l)
August 23,•In person stormwater sample collection site SRG.In person stormwater sampling at catch
2024 •Canal site CS3 and CS4 basin (n=l)
(Day 5 Canal sample at outflow by school (n=2)
targeted
stormwater
August 29,•In person stormwater sample collection,one per site.In person stormwater sampling at catch
2024 Sites included SRH,SRI,SRJ,SRK,SRL,SRM,SRN,basins (n=l 7)
(Day 6 SRO,SRP Canal sample at outflow by school (n=I)
targeted •In person stormwater sample collection site SRQ.
stormwater)Samples collected included SRQ-1,SRQ-2,SRQ-3,
SRQ-4,SRQ-5,SRQ-6,SRQ-7,SRQ-8
•Canal site CS5
September •In person stormwater sample collection,one per site.In person stormwater sampling at catch
10,2024 Sites included SRR,SRS,SRT,SRU,SRV,SRW,SRX,basins (n=9)
(Day 7 SRY,SRZ.
targeted
stormwater
September •Collected two PVC samples from the outfall at BBE on Canal sample at outflow by school (n=2)
19,2024 sample was collected at 3:36 pm and another was
collected at 4:15 om.
120
t t 4°$%
4u ~"I
i .@1s %%le«
e h h.to
"j«4«st%.s°)\•.~.$%
97a u ta $%Fzi 8 s%¥$%l
$%4 is%<1o
lo 4
+%%,~+%
·,9,,%rt,<io
\.$s .~
;+PU<10
»pa fa
4ta
Figure C.I:Groundwater sampling sites.Sites with a yellow "Y"were sites that were selected but were found to
be non-viable to clue excessive underground utilities and were therefore not drilled.The remaining 26 sites
without the yellow "X"were sampled.The site ID is given by a "G""F,or "R"(for proximity to gravity
sewer,force main,and stormwater conveyance system,respectively)followed by a number.The number below
the site ID corresponds to the enterococci concentration in the groundwater in units of MPN/100 mL.
P's113609
raog
two«at«r
i
>24196,
19863,
1%3P
•PS172410
o
rss {
824196
rs12 ?524196 '
ts.:7°eweetty»a
•PS1919040
Figure C.2:Puddle sampling sites.The site ID is given by "PS"followed by a number.The number below the
site ID corresponds to the enterococci concentration in the puddle water in units ofMPN/100 mL
121
>24196,1963 B51,8s9
a.w
£
»$196
»409%62.9 0
th i
«,es.
1
MM
Field-staged bottle sampling.
Figure C.3:Field-staged sampling sites.The site ID is given by "BS"followed by a number.The number
below the site ID corresponds to the enterococci concentration in the field-staged bottle sample in units of
MPN/100 mL.
-24196,>24196,»24196,
»24196,»24196,»24196,
>24196,»24196,
17329,24196,19869,SRC,SRE .%.tan +a
sRr os530
19863,24196,24196,
19863,>241986,-24196,
15531,1732,24196,
>24196,>24196,SA,SRD
48840,510,
81640,11300,
92080,7980,
8+0.4960,SF tSRN%%..%j"
djj010
',
I
,o..173290,>241960,>241960,198630,
173290,241960,
1ss310,173290
SRWd»241960
SRVA241960
SRL461310
In-person sampling.
Figure C.A:In-person runoff sampling sites.The site ID is given by "SR"followed by a letter.The number below the site
ID corresponds to the enterococci concentration in the in-person runoff samples in units of MPN/l 00 mL.
122
Figure Cc.5:PVC sampling sites.The site ID is given by "CS"for the outfall at BBE and "KS"."KO".and "KF"for the
Kayak launch for sam ples collected at the surface.I-foot,and 5-foot depths.Each site ID includes a number which
corresponds to the sequence of sam ple co llection.The num ber near the site ID corresponds to the entero cocci
concentration in the PVC sam ples in units of M PN/100 m L.
>2419 6,
19863,$s
319%5·42+1wo i,5Ro ts 22iiooi7vs7o,
s4198 63 0'
$%±
%%.
ra g%a
17329
\/
»24196,24196,
1730,5493,8664,11199,
15531,15s31.a440"%%8 .«io 'F$
+fll
«<10
Figur e C.6:Spatial distribution of entero cocci in water sam ples collected from the PVC catchm ent.Bro wn font
corresponds to gro undwater,purple corresponds to puddles,rust corresponds to field-staged bottle.black corresponds to
in-person runoff,and pink corresponds to sam ples collected from w ithin the PVC.The num ber near the site ID s
correspond to the ent ero cocci co ncentration in units of M PN/100 m L.
123
Table C.2:Data tables for groundwater samples.All times recorded as local time.MST data in main text.
Sample ID Location Description Sample Sample Sample Enterococci Field Water Phvsical Chemical Measurements in Laboratory
Collection Collection Collection (MPN/100 mL)Temperature pH Lab Water Salinity Turbidity Dissolved
Date Time Depth (ft)C)Temperature (psu)(ntu)Oxygen
(YYMMDD)(C)(mg/L)
Fl-A Grassy stretch W of white structure in 240723 11 :25 4 to 5.5 794 32.5/32 6.89 24.1 1.37 20.8 5.42middleofparkinglot.Comer 73°
St/Harding Ave
F2-A Parking lot located at SE end the 240723 10:46 4 to 5.5 <10 32/32 7.46 24.7 0.85 11.3 5.44intersection between 73"St/Harding
Ave
F3-A Grassy stretch along W of parking lot 240723 11 :05 4 to 5.5 51 33/33 7.45 24.6 0.31 18.4 5.85atthe comer of 73°St and Harding
Ave
F4-A Corner of73rd and Collins Ave,240723 8:00 7 to 8 <10 30/30 7.10 23.7 0.52 7.5 6.14grassyareainfrontofcommunity
center.SE intersection
F5-A Parking lot NE of intersection 240724 8:01 4 to 5 <10 31/33 7.20 27.9 0.35 2.5 4.83between74thSt/Harding Ave.SE
corner
F6-A Grassy area next to pump-station,W 240725 11 :30 4 to 5 216 32.5/31.5 6.53 26.7 28.61 85.1 3.12
of75th St and intersection of Dickens
Ave/75th St
F7-A W of Dickens Ave/75%street 240725 10:37 4 to 5 >24,196 33.5/32.5 6.61 27.4 1.18 27.0 0.84
intersection.Grassy patch W of
roundabout,along fence
F9-A In the grass of the median along 73°240723 9:43 4 to 5.5 1,337 31/31 6.82 23.3 1.51 76.4 4.92
between Carlyle Ave and Dickens
Ave
F10-A In the grass of the median along 73rd 240723 10:26 4 to 5.5 108 31.5/30.5 6.97 25.3 0.87 39.2 5.27
St between Harding Ave and Byron
Ave
Fl 1-A Grassy patch,S end of parking lot E 240723 11 :50 4 to 6 <10 34/34 7.26 23.5 0.38 1.5 5.24
of the comer of72d Street and
Harding,middle of lot
GI-A Along alley that runs perpendicular to 240724 11 :45 4 to 6 228 35.5/35.5 7.30 27.2 0.33 26.4 3.75
74/73d between Carlyle Ave and
BvronAve
G2-A Asphalt alley that runs perpendicular 240724 11:17 5 to 6 <10 33.5/33.5 7.81 26.8 0.2 25.5 4.73
to 74/73°between Harding Ave and
BvronAve
G3-A Asphalt along E sidewalk of Dickens 240725 9:34 4 to 5 145 32.5/32.5 7.51 27.1 0.43 3.5 4.23
Avenue,NE intersection corner
G4-A Grassy stretch SE of intersection 240724 9:05 7.5 to 8 <10 33/32.5 6.95 26.2 0.47 6.8 5.42
between 76 and Collins
124
Table C.2 (continued)
Sample ID Location Description Sample Sample Sample Enterococci Field Water Phvsical Chemical Measurements in Laboratory
Collection Collection Collection (MPN/100 mL)Temperature pH Lab Water Salinity Turbidity Dissolved
Date Time Depth (ft)C)Temperature (psu)(ntu)Oxygen
(YYMMDD)C)(mg/L)
G5-A Grassy patch east of the intersection 240723 8:35 6.5 to 7.5 <10 33.5/33.5 7.54 24.4 0.36 6.9 5.36between75StreetandCollins
Avenue
G7-A Asphalt along S sidewalk of 75%240725 10:07 4 to 5 <10 34/34.5 7.30 25.5 0.36 6.9 2.91StreetSEintersectioncomer
G8-A Grass of median along 73""and 240723 11:17 4 to 5.5 253 33.5/33.5 6.71 24.6 1.03 26.4 4.32CarlyleAveandByronAvenue
G10-A SW comer of Parkview Island Park,240723 8:55 4 to 5.5 <10 28.5/29 6.84 24.5 4.94 9.0 2.64
NE intersection of Bruce Street/Gary
Avenue
Gll-A Asphalt in alley between 75h Street 240724 10:39 4 to 5 <10 35/34.5 7.55 25.6 0.44 10.0 5.32
and 74"Street
G12-A Asphalt in alley between 75%Street 240724 12:00 5 to 6 85 34/34 7.20 25.3 0.39 13.6 4.47
and 74 Street
G13-A Grassy area NW comer of Altos Del 240724 10:06 8.5 to 9 10 32.5/32 7.01 27.7 0.46 72.2 4.93
Mar Park
G16-A Parkview Island Park grassy NE 240723 10:58 5 to 6 97 32.5/32 6.71 23.6 0.96 22.7 5.52
comer,SW comer
G17-A Grassy patch at intersection of 240723 9:15 3.5 to 5 761 31.5/32 7.21 22.7 0.51 82.1 5.34
73%/Wayne Avenue on Parkview
Island,SW section
RI-A Parking lot NE intersection between 240724 8:41 4 to 5 10 32.5/32 7.16 28.6 0.45 96.2 4.42
74 and Harding Avenue,NW comer
R2-A Grassy area N of North Beach 240725 9:08 4 to 5 10 33.5/32.5 7.11 26.3 0.69 9.9 4.40
Community Garden,W of
intersection Dickens Avenue/74
Street
R3-A Roundabout at Biscayne Elementary 240725 10:58 5 to 6 97 32.5/32 6.41 27.9 26.49 0.43 0.57
School drop-off,W of Dickens
Avenue/75%Street intersection
125
Table C.3:Data table for stormwater samples.All times recorded as local time.MST data in main text.
Sample Sample Phvsical Chemical Measurements in Laboratory
Sample Volume Field WaterSampleLocationDescriptionCollectionCollectionSampleProcessedforEnterococciTemperature Lab Water Dissolved
ID Date Type (MPN/100 rnL )pH Temperature Salinity Turbidity OxygenTimeenterococciC)(psu)(ntu)(YYMMDD)(mL)C)(mg/L)
BSI At the grate on the SE comer 240806 14:14 Field-10 >24,196 33.6 7.97 27.0 0.06 25.1 5.95
of the intersection of Collins staged
and 75th.Grate is on the E bottle
side of Collins Ave.
BS2 Grate on the NW comer of the 240806 11:40 Field-10 24,196 34.2 NIA NIA NIA NIA NIA
intersection of Collins Ave staged
and 74th St bottle
BS3 Grate on S end of Gary Ave.240806 15:20 Field-10 24,196 33.3 8.05 27.0 0.06 6.3 6.84
Grate is on the E side of Gary staged
Ave bottle
BS4 Grate on W side of the 240806 15:30 Field-10 >24,196 33.5 7.99 26.8 0.06 7.4 6.55
intersection Gary Ave and staged
Bruce St,SW comer of the bottle
Parkview Park
BS5 Storm-drain at the intersection NIA NIA Field-10 NIA NIA NIA NIA NIA NIA N/A
of 76/Collins Ave,E side of staged
Collins Ave bottle
BS6 Grate on the north side of 240806 15:00 Field-10 443 33.8 8.74 26.5 0.05 15.8 7.11
72nd St at the NE comer of staged
intersection of 72&/Collins bottle
BS7 Grate on the N side of 72nd St 240809 13:23 Field-10 11,199 28.2 8.6 23.5 0.02 11.5 6.96
at the NE comer of the staged
intersection of 72nd and bottle
Collins
BS8 Strom drain at the intersection 240809 13:36 Field-10 2,415 28.5 8.94 23.6 0.03 6.09 7.17
of Collins Ave and 73rd St E staged
of Collins Ave bottle
BS9 At the grate on the SE comer 240809 12:54 Field-10 19,863 30.5 8.66 24.0 0.05 21.8 7.04
of the intersection of Collins staged
and 75th.E of Collins Ave.bottle
BSI0 Grate on the NW comer of the 240809 12:45 Field-10 24,196 34.8 8.76 24.1 0.06 18.5 6.94
intersection of Collins Ave staged
and 74th St bottle
126
Table C.3 (Continued)
Sample Sample Phvsical Chemical Measurements in Laboratorv
Sample Volume Field WaterSampleCollectionSampleEnterococci Lab Water DissolvedLocationDescriptionCollectionProcessedforTemperatureSalinityTurbidityIDDateType(MPN/100 mL)pH Temperature OxygenTimeenterococciC)(psu)(ntu)(YYMMDD)(mL)C)(mg/L)
BS!1 Storm-drain at the northeast 240809 11:54 Field-10 >24,196 30.4 8.33 23.6 0.06 6.71 7.02
most point Parkview Island at staged
the intersection of Wayne bottle
Ave and Michael St
BS12 Storm-drain,W side of 240809 11 :59 Field-10 24,196 34.5 7.79 23.8 0.07 7.50 6.72
Parkview Island E side of staged
Gary Ave,building complex bottle
7311
BS13 Storm-drain at the northeast 240820 14:50 Field-10 14,136 28.6 8.41 23.7 0.06 18.6 7.26
most point Parkview Island at staged
the intersection of Wayne bottle
Ave and Michael St.Across
the street from SRA
BS14 Grate on west side of the 240820 15:03 Field-10 173,290 35.5 8.3 22.7 0.06 9.7 7.02
intersection Gary Ave and staged
Bruce St.At the southwest bottle
comer of the Parkview Park.
PSI Puddle at SE comer of74th 240725 8:10 Puddle 10 14,136 N/A 7.35 26.0 0.09 1.8 5.64
and Harding.Parking lot,
CVS
PS2 Storm-drain at the intersection 240725 9:10 Puddle 10 >24,196 NIA 7.97 24.0 0.27 3.5 3.93
of74th and Dickens
PS3 Puddle at the drain opening at 240725 9:40 Puddle 10 >24,196 NIA 7.00 25.9 0.19 9.7 1.72
the comer of76th and
Dickens
PS4 Puddle at the intersection of 240806 12:08 Puddle 10 1,399 35.1 8.71 26.1 0.11 3.40 7.08
73rd and Wayne Ave on
Parkview Island.On the west
side of Wayne Ave.
127
Table C.3 (Continued)
Sample Sample Phvsical Chemical Measurements in Laboratory
Sample Collection Sample Sample Volume Enterococci Field Water Lab WaterLocationDescriptionCollectionProcessedforTemperature Dissolved
ID Date Type (MPN/100 rnL)pH Temperature Salinity Turbidity OxygenTimeenterococciC)(psu)(ntu)(YYMMDD)(mL)C)(mg/L)
PS5 Puddle on the north side of 240806 11:40 Puddle 10 10,462 34.1 7.75 27.3 0.08 2.82 5.40
73rd St and just east of the
intersection of 73rd and
Dickens
PS6 Puddle in the southeast comer 240806 11:21 Puddle 10 24,196 31.8 7.25 24.6 0.10 2.10 4.38
of the public parking lot at the
comer of73rd and Harding.
PS7 Puddle on the North side of 240806 11:15 Puddle 10 6,131 38.3 7.76 23.0 0.15 6.1 5.82
75th St at the west end of the
street by the school.
PS8 Puddle on Parkview Island.240806 12:57 Puddle 10 >24,196 38 7.51 27.0 0.10 8.5 5.68
40 yds N of the intersection of
73rd and Wayne Ave
PS9 Puddle on the west most side 240806 14:18 Puddle 10 >24,196 30.5 7.71 24.4 0.07 3.8 5.89
of the parking lot on the north
side of the North shore librarv
PS10 Puddle at the east entrance to 240809 12:07 Puddle 10 861 37.4 8.64 26.6 0.04 10.4 7.34
the Parkview Island Park
parking lot
PSI 1 Puddle on the E side of Gary 240809 12:11 Puddle 10 3,609 34.4 8.70 25.7 0.05 8.58 6.94
Ave near BS12
PS12 Puddle in the alley between 240809 12:18 Puddle 10 >24,196 34.8 7.73 25.7 0.05 23.5 5.51
Carlyle and Byron and 74th
and 73rd
PS13 Puddle in the alley between 240809 12:22 Puddle 10 >24,196 35.4 8.06 24.8 0.06 6.81 6.46
Carlyle and Byron and 74th
and 75th
PS14 Puddle in the alley between 240809 12:30 Puddle 10 12,997 35.6 8.47 24.8 0.04 19.2 6.71
Harding and Byron and 74th
and 75th
PS15 Puddle in the alley between 240809 12:35 Puddle 10 17,329 34.4 8.00 25.2 0.04 3.45 6.54
Harding and Byron and 74th
and 73rd
128
Table C.3 (Continued)
Sample Sample Physical Chemical Measurements in Laboratory
Sample Volume Field WaterSampleCollectionSampleEnterococci Lab Water DissolvedLocationDescriptionCollectionProcessedforTemperatureSalinityTurbidityIDDateType(MP N/100 mL)pH Temperature OxygenTimeenterococciC)(psu)(ntu)(YYMMDD)(mL)C)(mg/L)
PS16 Southwest comer of 240820 15:03 Puddle 10 81,640 34.6 8.08 30.1 0.04 5.04 7.82
Parkview.West side of the
street
PS17 Southwest comer of 240820 15:08 Puddle 10 2,410 36 8.89 28.6 0.03 8.37 7.78
Parkview.
PS18 Comer of Dickens and 72nd.240820 15:19 Puddle 10 77,010 32 8.55 28.7 0.04 150 7.32
At the parking lot of the
tennis courts
PS19 Harding and 72nd.North side 240820 15:27 Puddle 10 19,040 35.2 8.22 29.1 0.05 17.6 7.47
of the street
PS20 75th and Ocean Ter.North 240820 15:35 Puddle 10 16,790 36.2 8.09 26.1 0.07 11.6 6.70
side of the street
PS21 75th and Abbot. South side of 240820 15:44 Puddle 10 25,810 32.3 8.47 28.2 0.05 5.25 7.05
the street
PS22 Abbot and 76th.South side of 240820 15:52 Puddle 10 129,970 31.3 8.46 25.8 0.08 7.34 7.20
the street
PS23 74th and Abbot.North side of 240820 16:00 Puddle 10 120,330 36.6 8.34 27.3 0.06 21.1 7.14
the street
PS24 Near the intersection of 73rd 240820 16:08 Puddle 10 98,040 36.8 7.82 26.0 0.07 17.7 6.63
and Harding on the south side
of73rd
PS25 West most end of75th at the 240820 16:19 Puddle 10 57,940 38.8 8.38 29.3 0.16 48.1 7.41
beginning of the roundabout
at the school
SRA Strom drain at the northeast 240806 13:09 In-person 1.0 >24,196 31.0 8.50 24.2 0.03 12.9 7.10
comer of the Parkview Island
Park
SRB Strom drain at intersection 240806 13:10 In-person 1.0 >24,196 36.9 7.97 26.3 0.11 27.1 6.02
Collins Ave/73"St,E side of
Collins Ave
SRC Storm-drain at the intersection 240806 13:15 In-person 1.0 >24,196 33.0 8.81 26.2 0.04 10.2 6.94
76/Collins Ave,E side of
Collins Ave
129
Table C.3 (Continued)
Sample Sample Physical Chemical Measurements in Laboratory
Sample Collection Sample Sample Volume Enterococci Field Water Lab WaterLocationDescriptionCollectionProcessedforTemperature Salinity Turbidity Dissolved
ID Date Type (MPNllO0 mL)pH Temperature OxygenTimeenterococciC)(psu) (ntu)(YYMMDD)(mL)C)(mg/L)
SRD Strom drain at the northeast 240809 11:37 In-person 1.0 >24,196 28.7 8.79 26.2 0.07 24.0 7.26
comer of the Parkview Island
Park
SRE Storm-drain at the intersection 240809 13:07 In-person 1.0 24,196 30.7 8.29 26.5 0.07 30.5 7.00
76/Collins Ave,E side of
Collins Ave
SRF Parkview Island,W side of 240820 14:30 In-person 1.0 92,080 31.9 8.71 25.8 0.05 16.7 7.38
Wayne Ave,half-way up
street at storm drain
SRG Grate at intersection 240823 NIA In-person 1.0 10,760 NIA NIA NIA NIA NIA NIA
73%/Dickens,N side of 73"St
SRH Storm-drain SW comer of 240829 NIA In-person 1.0 >241,960 NIA 7.57 23.2 0.24 28.4 5.97
intersection 74/Carlyle Ave
SRI Storm-drain at SW comer of 240829 NIA In-person 1.0 11,590 NIA 7.99 21.9 0.17 6.67 6.74
intersection 74/Byron Ave
SRJ Storm-drain at intersection 240829 NIA In-person 1.0 38,730 NIA 7.79 21.7 0.16 24.2 6.65
74/Dickens along W side
SRK Storm-drain at NW comer of 240829 NIA In-person 1.0 86,640 NIA 8.01 20.4 0.2 58.9 6.17
the intersection Dickens/72
SRL Storm-drain at SE comer of 240829 NIA In-person 1.0 61,310 NIA 7.88 21.3 0.42 48.0 6.27
intersection of 72%/Abbot
Ave
SRM Storm-drain at SE comer of 240829 N/A In-person 1.0 15,520 NIA 8.50 22.2 0.08 38.4 6.78
intersection 737%/Ocean Ter.
Along S of 73%,outside
parking lot
SRN Storm-drain at NW comer of 240829 NIA In-person 1.0 241,960 NIA 8.36 21.6 0.09 20.8 6.76
intersection 73%/Carlyle Ave
SRO Storm-drain at SE comer of 240829 NIA In-person 1.0 >241,960 NIA 8.39 22.0 0.06 9.34 6.64
intersection 76"/Byron Ave
SRP Storm-drain at intersection of 240829 NIA In-person 1.0 77,010 N/A 8.91 23.3 0.09 95.0 6.87
73%/Carlyle Ave,S of738
130
Table C.3 (Continued)
Sample Sample Physical Chemical Measurements in Laboratorv
Sample Collection Sample Sample Volume Enterococci Field Water Lab WaterLocationDescriptionCollectionProcessedforTemperature Salinity Turbidity Dissolved
ID Date Type (MPN/100 mL)pH Temperature OxygenTimeenterococciC)(psu)(ntu)(YYMMDD)(mL)C)(mg/L)
SRQ Storm-drain at NW comer of 240829 NIA In-person 1.0 173,290 NIA 7.81 23.5 0.08 5.44 6.69
intersection of 73"%/Byron
Ave
SRR Storm-drain at the intersection 240910 16:16 In-person 1.0 198,630 NIA 7.14 27.5 3.02 9.12 4.81
of 75/Dickens,SW comer of
the intersection
SRS Storm-drain at intersection 240910 16:20 In-person 1.0 >241,960 NIA 7.16 27.0 0.43 11.3 6.22
76"/Carlyle SW corer
SRT Intersection of 75/Harding 240910 16:26 In-person 1.0 6,310 NIA 8.49 26.2 0.31 1.72 7.53
SRU Storm-drain in SE section of 240910 16:31 In-person 1.0 46,110 NIA 7.68 27.3 0.39 56.5 6.43
parking lot of library on
75%/Collins
SRV Storm-drain at the end E end 240910 16:09 In-person 1.0 241,960 NIA 7.35 27.4 0.13 10.3 5.32
of 74 St past Collins Ave,S
side
SRW Long storm-drain at comer of 240910 16:03 In-person 1.0 >241,960 NIA 7.49 27.0 0.12 8.3 5.88
Harding/74 SE corner
SRX Storm-drain at intersection 240910 15:51 In-person 1.0 129,970 NIA 7.59 26.5 0.23 35.4 5.53
72%/Collins,NW corer
Previous sampling site)
SRY Storm-drain along S side of 240910 15:45 In-person 1.0 104,620 NIA 7.56 26.7 0.23 573 5.4
72"on E end of tennis courts
SRZ Storm-drain on SE end of 240910 16:41 In-person 1.0 155,310 NIA 7.71 25.5 0.19 10.6 5.73
Parkview Island,S side of
road
N/A =Not available
131
Table C.4:Data table for PVC samples collected at the Kayak Launch and at the Biscayne Beach Elementary (BBE)Outfall.All times recorded as local time.MST
data in main text.
Sample Location Sample Sample Sample Water Level Measured Sample Enterococci Field Water Physical Chemical Measurements in Laboratorv
ID Description Collection Collection Collection Measurement PVC Volume (MPNll00 Temperature pH Lab Water Salinity Turbidity Dissolved
Depth (ft)Date Time Time Water Processed mL)C)Temperature (psu)(ntu)Oxygen
(YYMMDD)Surface for C)(mg/L)
Elevation enterococci
(mL)
KS0l Kayak Launch 0 240815 6:10 6:05 38 10 9,208 31.5 7.35 N/A 34.53 1.8 5.53
KS02 Kayak Launch 0 240815 7:05 7:00 39 10 2,924 32.1 7.42 NIA 35.48 0.9 5.8
KS03 Kavak Launch 0 240815 8:05 8:00 43 10 216 32.3 7.41 NIA 35.2 0.8 5.5
KS04 Kayak Launch 0 240815 9:05 9:00 48 10 275 32.1 7.54 NIA 35.3 1.3 6.22
KS05 Kayak Launch 0 240815 10:05 10:00 53 10 305 32.4 7.49 NIA 33.87 1.8 6.18
KS06 Kayak Launch 0 240815 11:05 11 :00 57 10 313 32.8 7.44 NIA 35.3 1.1 5.67
KS07 Kayak Launch 0 240815 12:05 12:00 59.5 10 373 33.33 7.5 NIA 30.88 2.3 5.51
KS08 Kayak Launch 0 240815 13:05 13:00 58.4 10 148 34.3 7.64 NIA 34.93 0.7 5.85
KS09 Kayak Launch 0 240815 14:05 14:00 54.7 10 30 35.5 8.05 NIA 35.7 1.3 7.73
KSl0 Kayak Launch 0 240815 15:02 14:57 50 10 98 35.3 7.96 NIA 34.37 1.1 7.82
KSll Kayak Launch 0 240815 16:03 15:58 42.8 10 645 33.7 8.83 NIA 34.07 0.9 7.5
KS12 Kayak Launch 0 240815 17:05 17:00 38.6 10 2,035 31.3 7.76 NIA 0.19 1.5 8.73
KO0l Kayak Launch 1 240815 6:15 NIA NIA 10 457 32.2 7.46 NIA 35.46 0.7 6.22
KO02 Kavak Launch 1 240815 7:07 NIA NIA 10 399 32.3 7.5 NIA 36.16 0.9 6.23
KO03 Kavak Launch 1 240815 8:04 N/A NIA 10 538 32.3 7.45 NIA 36.12 1.0 5.52
KO04 Kayak Launch 1 240815 9:45 NIA N/A 10 209 32.2 7.54 NIA 36.3 1.4 6.22
KOO5 Kayak Launch 1 240815 10:50 NIA NIA 10 393 32.7 7.51 NIA 35.78 2.0 6.27
KO06 Kayak Launch 1 240815 11 :34 NIA NIA 10 52 32.9 7.49 NIA 35.99 1.2 5.66
KO07 Kayak Launch 1 240815 12:16 NIA NIA 10 52 33.2 7.61 NIA 36.84 1.4 6.33
KOO8 Kavak Launch 1 240815 13:05 NIA NIA 10 223 33.5 7.56 NIA 36.14 1.7 5.29
KO09 Kayak Launch 1 240815 14:11 NIA NIA 10 142 35 8.05 NIA 35.79 0.9 7.74
KOl0 Kayak Launch 1 240815 15:01 NIA NIA 10 41 35.2 7.86 NIA 35.8 1.1 8.2
KOll Kayak Launch 1 240815 15:53 NIA NIA 10 109 33.7 7.83 NIA 34.08 1.0 7.5
KO12 Kayak Launch 1 240815 17:05 NIA NIA 10 369 32.1 7.73 NIA 32.93 1.8 7.26
KF 0I Kayak Launch 5 240815 6:21 NIA NIA 10 487 32.6 7.49 NIA 36.5 1.4 6.16
KF02 Kavak Launch 5 240815 7:11 NIA NIA 10 350 32.7 7.51 NIA 36.54 2.4 6.1
KF03 Kavak Launch 5 240815 8:50 N/A NIA 10 388 32.6 7.48 NIA 36.41 5.7 5.87
KF04 Kayak Launch 5 240815 NIA N/A NIA NIA NIA 32.6 7.51 NIA 36.39 NIA 5.55
KF 05 Kayak Launch 5 240815 10:50 NIA NIA 10 450 32.8 7.5 NIA 36.71 8.3 5.48
KF 06 Kavak Launch 5 240815 11:33 NIA NIA 10 651 33.2 7.59 NIA 36.95 9.6 6.67
KF 07 Kayak Launch 5 240815 12:18 N/A NIA 10 529 33.2 7.61 NIA 36.84 6.4 6.33
KF 08 Kayak Launch 5 240815 13:10 NIA NIA 10 616 33.2 7.61 NIA 36.66 3.5 6.11
132
Table C.4 (Continued)
Sample Location Sample Sample Sample Water Level Measured Sample Enterococci Field Water Physical Chemical Measurements in Laboratory
ID Description Collection Collection Collection Measurement PVC Volume (MPNllO0 Temperature pH Lab Water Salinity Turbidity Dissolved
Depth (ft)Date Time Time Water Processed mL)C)Temperature (psu)(ntu)Oxygen
(YYMMDD)Surface for C)(mglL)
Elevation enterococci
(mL)
KO09 Kayak Launch 1 240815 14:11 NIA NIA 10 142 35 8.05 NIA 35.79 0.9 7.74
KOl0 Kayak Launch 1 240815 15:01 NIA NIA 10 41 35.2 7.86 NIA 35.8 1.1 8.2
KOll Kayak Launch 1 240815 15:53 NIA N/A 10 109 33.7 7.83 N/A 34.08 1.0 7.5
KO12 Kavak Launch 1 240815 17:05 NIA N/A 10 369 32.1 7.73 NIA 32.93 1.8 7.26
KF 0l Kayak Launch 5 240815 6:21 NIA NIA 10 487 32.6 7.49 NIA 36.5 1.4 6.16
KF02 Kayak Launch 5 240815 7:11 NIA NIA 10 350 32.7 7.51 NIA 36.54 2.4 6.1
KF 03 Kayak Launch 5 240815 8:50 NIA NIA 10 388 32.6 7.48 NIA 36.41 5.7 5.87
KF 04 Kayak Launch 5 240815 N/A NIA NIA NIA NIA 32.6 7.51 NIA 36.39 NIA 5.55
KF 05 Kavak Launch 5 240815 10:50 NIA NIA 10 450 32.8 7.5 NIA 36.71 8.3 5.48
KF 06 Kayak Launch 5 240815 11:33 NIA NIA 10 651 33.2 7.59 NIA 36.95 9.6 6.67
KF 07 Kayak Launch 5 240815 12:18 NIA NIA 10 529 33.2 7.61 NIA 36.84 6.4 6.33
KF 08 Kayak Launch 5 240815 13:10 NIA NIA 10 616 33.2 7.61 NIA 36.66 3.5 6.11
KF 09 Kayak Launch 5 240815 14:14 NIA NIA 10 368 33.8 7.79 N/A 36.68 3.2 6.67
KFl0 Kayak Launch 5 240815 15:04 N/A N/A 10 187 34.5 7.86 NIA 36.43 3.9 7.81
KFll Kavak Launch 5 240815 15:56 NIA NIA 10 327 34 7.81 NIA 36.72 4.4 8.17
KF12 Kayak Launch 5 240815 17:03 NIA NIA 10 243 34.1 7.56 NIA 36.3 4.0 7.73
CSl BBE Outfall 0 240805 12:35 NIA NIA 10 17,329 NIA 7.29 23.8 20.03 0.76 5.54
CS2 BBE Outfall 0 240820 16:27 NIA NIA 1.0 198,630 29.5 7.10 26.7 13.74 1.91 5.33
CS3 BBE Outfall,0 240823 13:29 NIA N/A 1.0 980 29.2 7.35 21.9 35.64 1.04 5.37
submerged
CS4 BBE Outfall,0 240823 15:30 NIA NIA 1.0 740 30.8 7.26 23.0 35.76 0.73 4.22
70%
submerged
CS5 BBE Outfall 0 240829 NIA NIA NIA 1.0 2,720 NIA 6.91 23.5 32.66 1.73 4.76
CS6 BBE Outfall,0 240919 15:36 NIA NIA 1.0 2,620 NIA 7.03 23.5 16.66 6.35 4.98
mostly
submerged
CS7 BBE Outfall,0 240919 16:15 NIA NIA 1.0 8,650 NIA 7.1 23.7 14.75 6.67 5.31
submerged
a NI A =Not available or not applicable
133
Fl F2
£:Still"litIll sat
Grassy stretch W of white structure in middle of
arking lot.Corner 73d Street and Harding Avenue
f
Parking lot located at SE end the intersection between
73'St/Harding Ave
F3 F4
Grassy stretch along W of parking lot at the corner of
73%and Harding Comer of 73d and Collins Ave,grassy area in front of
community center.Southeast intersection
F5 F6
Parking lot NE of intersection between 74 St/Harding
Ave.Southeast corner
>I ,,~
Grassy area next to pump-station.W of 750 St and
intersection of Dickens Ave/750 St
F7
In the grass of the median along 73'St between
Harding Ave and Byron Ave
fi ifis's'wsnil%hi"?
Grassy patch,S end of parking lot E of the comer of
72'Street and Harding,middle of lot
Figure C.7:Photos of groundwater sampling locations.
134
Gl -
L&"
Along alley that runs perpendicular to 74h/73d between
Carlyle Ave and Byron Ave
Asphalt along E sidewalk of Dickens Avenue.NE
intersection corner
G5
Grass of median along 73hand Carlyle Ave and Byron
Avenue
Gl 1
Asphalt alley that runs perpendicular to 740/73between
Hardin:'ron Ave
G4
Grassy stretch SE of intersection between 76 and Collins
G7
Asphalt along S sidewalk of 75%Street SE intersection corner
GlO
$
SW corner of Parkview Island Park,NE intersection of Bruce
Street/Gary Avenue
Gl2
Asphalt in alle between 75h Street and 74 Street
Figure C.7 (continued):Photos of groundwater sampling locations.
135
Grassy patch at intersection of 73d/Wayne Avenue on
Parkview Island,SW section
E?"Pf;o 333 »
74,«'9.3
$f 8,
4 illy "g .
out».K :·,¢
#sSkill:tf%!fo}',1ht
r
Grassy area N of North Beach Community Garden.W of
intersection Dickens Avenue/74"street
Parking lot NE intersection between 74%and Harding Avenue.
NW corner
R3
Roundabout at Biscayne Elementary School drop-off.W of
Dickens Avenue/75%Street intersection
Figure C.7 (continued):Photos of groundwater sampling locations.
136
Asphalt area next to E sidewalk of Byron Ave.SE
comer of intersection 77h/pron Ave
Asphalt area NW of intersection Harding Ave/76 st
F8
~
Asphalt area,130ft S of intersection Dickens
Ave/75 st
Figure C.8:Photos of sites planned for groundwater sampling but deemed non-viable due to conflicts with
underground utilities.
137
PSI PS2
Storm drain at the intersection of 74"/E side of Dickens
PS4
Drain opening at the corner of 76 E side of Dickens
PS5
N side of 73dE of the intersection of 73"%/Dickens
PS7
N side of 75h 4t W end of the street,near elementary school
PS9
W side of parking lot to the N of North Shore Library E entrance to Parkview Island Park parking lot
Figure C.9:Photos of puddle sampling sites.
138
+A±3.Harding and 72,N side of the street
Figure C.9 (continued):Photos of puddle sampling sites.
139
PS12
75%and Ocean Ter.N side of the street
74 and Abbot.N side of the street
Figure C.9 (continued):Photos of puddle sampling sites.
PS22
Near intersection 73%/Harding on the S side of 73rd
140
BSI BS2
ta4
lit
Strom drain at the northeast corner of the Parkview
Island park
!S'6oaf#e.me'.luc.di.leIii7 sir »
Stromdrain at intersection Collins Ave/73d St.E side
of Collins Ave
BS3 BS4
Storm drain at the intersection 76%/Collins Ave.E side
of Collins Ave
Strom drain at the northeast comer of the Parkview
Island park
BS5 BS6
Storm drain at the intersection 76%/Collins Ave.E side
of Collins Ave
hf.l«7wiwosoil
Parkview Island.W side of Wayne Ave.half-way up
street at storm drain
BS7 BS8
Grate at intersection 73"%Dickens.N side of 73"St
Grate on the SE corner of intersection Collins/75
»
fl
Storm drain SW corer of intersection 74"/Carlyle Ave
BSlO
4lied#dhe
Grate on the NW corner of intersection€Collins/74%st
Figure C.IO:Photos of "field-staged bottle"sampling locations.
141
BSl 1
Storm drain at NE most point Parkview Island at
intersection Wayne Ave/Michael St
BS13
Storm drain at NE most point Parkview Island at the
intersection Wayne Ave/Michael St
Stonn drain on the W side of Parkview Island on the
east side of Gar Ave
BS12
Grate W of intersection Gary Ave/Bruce St.SW corer
of Parkview Park
Figure C.10 (continued):Photos of "field-staged bottle""sampling locations.Samples BS 11 and BS12 taken
in-person but given a bottle sample (BS)identifier.
142
Strom drain at the northeast comer of the Parkview
Island ark
SRC:«
A
Storm drain at the intersection 76"/Collins Ave.E side
of Collins Ave
SRE
·1
watt fl
Storm drain at the intersection 76"/Collins Ave
Grate at intersection 73%Dickens.N side of 73'St
SRI
Storm drain at SW corner intersection 74%/Byron Ave
SRB
i,
Strom drain at intersection Collins Ave/73"St.E side
of Collins Ave
SRD
Strom drain at the northeast corner of the Parkview
Island park
SRF
Parkview Island.W side of Wayne Ave storm drain
SRH
Storm drain SW corner of intersection 74/Carlyle Ave
SRJ
Storm drain at intersection 74h/Dickens along W side
Figure C.II:Photos of "in-person runoff"sampling locations.
143
SRK
Stormdrain at NW comer of intersection Dickens/72d
SRM
Storm drain at SE corner of intersection 73'/Ocean Ter.
Stormdrain at SE comer of intersection 76%Byron Ave
G·
son a4~«Nw corer of intersection 73Byron Ave
SRS
Storm drain at intersection 76"/Carlyle SW comer
SRL
Storm drain at SE comer of intersection of 72%/Abbot
Ave
SRN
-•?idle.
Storm drain at NW comer of intersection 73%/Carl le Ave
SRP
Storm drain at intersection of 73Carlyle Ave,S of 73d
SRR
-Storm drain at the intersection of 75%/pickens.SW comer
Intersection of 75/Harding
Figure C.11 (continued):Photos of "in-person runoff"sampling locations.
144
SRU
Iit&is
~·'......'
et
Stormdrain in parking lot of library on 75/Collins
SRW
Lon storm drain at comer of Harding/74 SE corner
SRY
Storm drain along S side of 72 on E end of tennis courts
SRV
Storm drain at the end E end of 74"St past Collins Ave
SRX
Storm drain at intersection 72%/Collins.NW corner
SRZ
",
7
we/'ii
'Storm drain on SE end of Parkview Island.S side of road
Figure C.II (continued):Photos of "in-person runoff sampling locations.
145
CSl
Storm drain leading into the canal,in line with
structure of elementary school
CS3
High tide,outfall completely submerged (100%)
CS5
Storm drain leading into the canal,in line with
structure of the elementa school
CS7
CS2
Storm drain leading into the canal,in line with
structure of elementa school
CS4
@rd
Storm drain leading into the canal,in line with
structure of elementa school,70%submer ed
CS6
'#sOutfallatelementaryschool,"low tide,"but still
mostly submerged.Canal/outfall water mixture
Outfall at elementary school,"low tide,"but still 50%
submer ed.Pure!outfall water
Figure C.12:Photos of "in-person runoff'sampling locations.
146
nee#±.egg.
E IM T,
Figure C.13:Illustration of process used to identify underground utilities using ground penetrating radar.The
roller device is used to obtain an overall mapping of the utilities and the handheld device (in the foreground on
the grass)is used to obtain finer resolution of the underground utilities.
Sy
It/•ra7%r
j
•
Figure C.14:Illustration of groundwater sample collection from behind the pickup truck mounted drill rig.
147
Figure C.15:Illustration of stormwater sampling.Top two square photos illustrate the field-staged bottle
sample set up hanging immediately below the catch basin grate.Top right photo illustrates puddle sampling.
The bottom photo illustrates the set up for in-person runoff sampling requiring the removal of the top grate or
manhole cover for manual placement of a bottle to collect water as it falls into the catch basin.
148
Figure C.16:Photo of sample collection set up at the Kayak Launch towards the beginning of the 12-hour
sampling event.
149
Figure C.17:Photo of outfall at BBE
150
Figure C.18:Photo of animal feeding station of bread and donuts taken on January 31,2025,near the entrance
to the Kayak Launch.Prior to taking the photo,a flock of birds were seen at the station.These birds flew away
once the station was approached to take this photo.
151
APPENDIXD
LABORATORY PROCESSING DETAILS FOR MST AND
ENTEROlA MARKERS
152
APPENDIXD
LABORATORY PROCESSING DETAILS FOR MST AND
ENTEROlA MARKERS
Environmental water samples (from groundwater,stormwater,and the PVC)were aseptically collected into
sterile containers and transported back to the laboratory on ice as previously described in the main text.For
qPCR analysis of MST and the EnterolA marker analysis,up to 500 mL water samples were aseptically filtered
onto sterile mixed cellulose ester (MCE)type membrane filters,47 mm diameter,0.45 µm pore-sized (GN-6,
Pall),to collect the bacterial population of the water sample onto the membrane filter.For samples that were too
turbid to filter a full 500 mL of water sample,the water sample was passed through the filter until clogging.For
each individual filter,the actual volume of water sample that was passed through the filter was recorded,and
the filter was assigned a unique filter sample ID tracking number.For tracking purposes,all filter samples were
labeled with multiple cross-referenced IDs that included both a unique filter ID number label,and an
independent label of a unique combination of sample site ID plus date in YYMMDD format.After filtration,the
filters were aseptically folded with sterile forceps and placed into sterile 5 mL microcentrifuge tubes containing
1,500 µL of 1Zymo DNA/RNA Shield (a nucleic acid preservative by Zymo Research Corporation that keeps
both DNA and RNA molecules stable for extended periods at room temperature)and stored frozen at -80°C
until later eDNA extraction and purification.The Zymo DNA/RNA Shield can also act directly as a bacterial
lysis buffer for nucleic acid purification in combination with bead-beating homogenization (Zymo Research).
For extraction of eDNA for this project,the preserved filter tubes with the DNA/RNA Shield were first brought
to room temperature,then both the filter and its associated DNA/RNA shield preservative were aseptically
transferred to sterile Zymo Bead-Basher tubes (with a mixture of 0.1 mm and 0.5 mm ultra-high-density beads)
from the Zymobiomics 96 MagBead DNA Kit (Zymo Research),and all cells on the filter were lysed releasing
their DNA content into the lysate by 5 rounds of bead-beating homogenization for 60 sec each at an impact
speed of 6.0 mis in a FastPrep-24 instrument (MP Biomedicals).The resulting lysate was loaded onto
KingFisher 96-well deep well plates and the eDNA was purified using a KingFisher Flex automated nucleic
acid purification system (Thermofisher),using the Zymobiomics 96 MagBead DNA Kit (Zymo Research)as
per manufacturer directions.Final purified eDNA was eluted into sterile 1 x TE buffer,and the purified DNA
was stored at -20 °C until later qPCR analysis.
The purified eDNA from water samples was analyzed by qPCR in 96-well reaction plates on an Applied
Biosystems StepOnePlus real-time qPCR system (Thermofisher Applied Biosystems),using the protocols
specific for each gene marker target:[I]"HF183 Taqman"human-source Bacteroides as per EPA method 1696
(US EPA 2019)with minor modifications noted below;[2]"DG3 Taqman"canine-source Bacteroides as per
Green et al., 2014 (with minor modifications noted below);and [3]"GFD SybrGreen"general bird Helicobacter
as per Green et al.,2011 (with minor modifications noted below);[4]"Gull2"seagull/seabird-source as per
Sinigalliano et al.,2013 (with minor modifications noted below;[5]"EnterolA"general enterococci as per EPA
method 1611 (US EPA,2012a)with minor modifications noted below.The minor modifications for all these
assays were:25 µL volume final reactions per well were used;2 µL of template eDNA was added per reaction;
12.5 µL of 2x qPCRBIO Probe Master Mix with HI ROX (PCR Biosystems)used per reaction for HF183,
DG3,Gull2,and EnterolA,while 12.5 µL of 2x qPCRBIO SyGreen Master Mix with HI ROX (PCR
Biosystems)was used per reaction for GFD.In the case of EnterolA,quantitation was not done using the CCE
cell calibrators method as per EPA Method 1611,but by quantitation using a standard curve with the newer
EPA designed NIST Standard Reference Material plasmid SRM-2917 in the same fashion as EPA Method 1696
but using the EnterolA primers and probes from EPA Method 1611.All standard curves for quantitation of
EnterolA,HF183,DG3,and GFD were constructed using NIST-certified quantitative Standard Reference
Material#SRM-2917 from the National Institute of Standards and Technologies.(This is a multi-target plasmid
positive control developed by the US EPA for these MST assays,at known certified concentrations,and made
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commercially available by NIST).The Gull2 seagull target sequence is not on this NIST control plasmid,so for
the seagull Gull2 assay,standard curves were generated using known concentrations of synthetic double-
stranded DNA gene fragments of the target sequence that had been synthesized by Integrated DNA
Technologies (IDT.com).Triplicate standard concentration curves were run on each qPCR plate,and each
environmental DNA sample was analyzed in triplicate,along with No-Template negative controls,as well as
Inhibition Amplification Controls.The NIST SRM-2917 plasmid can provide certified concentration positive
control standard curves for a wide variety of MST targets,including Enterococci Entero 1 A by EPA Method
1611.1, human Bacteroides HFl 83 by EPA Method 1696,dog Bacteroides DG3,bird Helicobacter GFD,(as
well as many other bacterial and viral MST targets).The quality control and assurance metrics and performance
acceptance criteria for the qPCR done in this study was as per EPA Method 1696.The Lower Limit of
Quantification (LLOQ)per reaction was determined by the upper 95%prediction interval of the lowest reliably
repeatable concentration standard (l O copies),and the r-square of the linear regression of the standard curves
and the amplification efficiency of all run plates were well within the acceptance criteria for the standard curves
as defined in EPA Method 1696.No Template Controls (NTCs)were negative,and Inhibition Amplification
Controls were within acceptable ranges of variation from Method Blank inhibition concentration controls (i.e.,
the test sample Cq mean within 3 standard deviations of the mean Cq of the triplicate control wells),indicating
there was no significant environmental inhibition of the qPCR reactions observed under these circumstances.
Taking into consideration the water sample volumes filtered (keeping in mind that the actual water sample
volumes varied by sample),the volume of lysate generated and purified,the volume of resulting the resulting
pure eDNA elutions,and the volume of purified eDNA eluate used in qPCR reactions,a consensus mean of
Environmental Lower Limit of Quantitation (eLLOQ)was estimated to be approximately 50 copies per 100 mL
of original water sample.Any qPCR measurements of environmental target concentrations below this value for
these samples (as analyzed under these conditions)are hereby designated as "Detected but Not Quantified"or
"DNQ".While we may also report values below this number here in certain tables or on graphs for purposes of
graphic visualization,or comparison to combined multi-target RBTs,ANY sample designated as "DNQ"should
be recognized as not necessarily reliable,and these low levels of target detection could also possibly be due (at
least in part)to "background noise".Therefore,any values of these environmental MST markers from these
sampling and processing conditions that are below a value of 50 copies/100mL of water sample should be
viewed with skepticism and be considered as insignificant.Note that this DNQ range is well below the typical
Risk Based Threshold for public health decision making (unless one is considering extremely low levels of
human marker reducing the RBT of bird markers),so any samples with values below the eLLOQ that are in the
DNQ range should not affect any decision-making based on health risk estimates (except for a few instances of
combined bird and very low-level human markers).
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APPENDIXE
RESPONSE TO WRITTEN COMMENTS FROM THE
COMMUNITY
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APPENDIXE
RESPONSE TO WRITTEN COMMENTS FROM THE
COMMUNITY
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