PBSD MSTBU Agenda 10/30/2023PELICAN BAY SERVICES DIVISION
Municipal Service Taxing and Benefit Unit
NOTICE OF PUBLIC MEETING
OCTOBER 30, 2023
THE CLAM BAY COMMITTEE OF THE PELICAN BAY SERVICES DIVISION WILL
MEET AT 1:30 PM ON MONDAY, OCTOBER 30 AT THE TRUIST BANK BUILDING,
801 LAUREL OAK DRIVE, SUITE 102, NAPLES, FLORIDA 34108.
AGENDA
1. Pledge of Allegiance
2. Roll call
3. Agenda approval
4. Approval of 5/2/2023 meeting minutes
5. Audience comments
6. "Approval of draft plans for proposed 2024 dredging of Clam Pass
7, 2022 Clam Bay Water Quality Report
8. Adjournment
"indicates possible action items
ANY PERSON WISHING TO SPEAK ON AN AGENDA ITEM WILL RECEIVE UP TO THREE (3) MINUTES PER
ITEM TO ADDRESS THE BOARD. THE BOARD WILL SOLICIT PUBLIC COMMENTS ON SUBJECTS NOT ON
THIS AGENDA AND ANY PERSON WISHING TO SPEAK WILL RECEIVE UP TO THREE (3) MINUTES. THE
BOARD ENCOURAGES YOU TO SUBMIT YOUR COMMENTS IN WRITING IN ADVANCE OF THE MEETING.
ANY PERSON WHO DECIDES TO APPEAL A DECISION OF THIS BOARD WILL NEED A RECORD OF THE
PROCEEDING PERTAINING THERETO, AND THEREFORE MAY NEED TO ENSURE THAT A VERBATIM
RECORD IS MADE, WHICH INCLUDES THE TESTIMONY AND EVIDENCE UPON WHICH THE APPEAL IS TO
BE BASED, IF YOU ARE A PERSON WITH A DISABILITY WHO NEEDS AN ACCOMMODATION IN ORDER TO
PARTICIPATE IN THIS MEETING YOU ARE ENTITLED TO THE PROVISION OF CERTAIN ASSISTANCE.
10/24/2023 11:26 AM
PELICAN BAY SERVICES DIVISION
CLAM BAY COMMITTEE MEETING
MAY 2, 2023
The Clam Bay Committee of the Pelican Bay Services Division met on Tuesday, May 2 at 1:00
p.m. at the PBSD Office in the Truist Building, 801 Laurel Oak Drive, Naples, Florida 34108. In
attendance were:
Clam Bay Committee
Denise McLaughlin, Chair
Pelican Bay Services Division Staff
Neil Dorrill, Administrator
Chad Coleman, Operations Manager
Darren Duprey, Supervisor — Field I (absent)
Also Present
Mohamed Dabees, Humiston & Moore
Michael Rodburg (absent)
Rick Swider
Dave Greenfield, Supervisor -Field II
Karin Herrmann, Project Manager I
Lisa Jacob, Project Manager II
Barbara Shea, Admin. Support Spec. II
Michael Fogg, PBSD Board
APPROVED AGENDA (AS PRESENTED)
1. Pledge of Allegiance
2. Roll can
3. Agenda approval
4. Approval of 1/26/2023 meeting minutes
5. Audience comments
6. Collier County Coastal Storm Risk Management Study Update (Dr. Dabees)
7. Update on Clam Bay tide gauges
8. Adjournment
ROLL CALL
Mr. Rodburg was absent and a quorum was established.
Mr. Swider motioned, Ms. McLaughlin seconded to approve the agenda as
The motion carried
Mr. Swider motioned, Ms. McLaughlin seconded to approve the I/26/2023 meeting
minutes as presented. The motion carried unanimously.
Pelican Bay Services Division Clam Bay Committee Meeting
May 2, 2023
AUDIENCE COMMENTS
Ms. Ashley Jenkins and Ms. Shelley McKernan introduced themselves and commented that
they attended the April Big Cypress Basin Board April meeting as well as the USACE (U.S. Army
Corps of Engineers) public meetings last week on the Collier County Coastal Storm Risk Management
Study. They commented that they are advocates for water quality improvements in the County and
are studying these issues and possible solutions. Ms. Jenkins and Ms. McKernan stated that they do
not represent any organization, and that they are attending this meeting for educational purposes.
Dr. Dabees commented that Clam Bay is a natural preserve area, and suggested that it is an
example of how coastal communities should be developed. He noted that the PBSD continuously
manages the mangroves and the bay, and that we have a water quality monitoring system in place.
COLLIER COUNTY COASTAL STORM RISK MANAGEMENT STUDY UPDATE
Dr. Mohamed Dabees, Coastal Engineer with Humiston &Moore, provided an update on what
was learned
at last week's USACE 3-day chan•ette (for stakeholders) and two public meetings on the
Collier
County Coastal Storm Risk and Resiliency Management Study. Highlights included the
following.
•
The USACE provided a review of their goals for this study. As their process goes forward,
they are hoping to improve communication and engagement with stakeholders and the public.
There was a lot of public interest at these public meetings.
•
Mr. Dorrill, representing the PBSD and Mr. Hoppensteadt, representing the PBF attended the
charrette.
•
Our point of contact for this study going forward will be the County's new Director of
Community Planning and Resiliency, Chris Mason. An advisory body will be formed with
members representing all areas of the County as well as the two cities.
•
Mr. Dorrill and Mr. Hoppensteadt plan to schedule a meeting with Mr. Mason to discuss
Pelican Bay's interests and concerns relating to the study.
•
The Collier County CAC (Coastal Advisory Committee) was informed that going forward
any CAC members will be speaking as individuals (and not as committee members) on this
study.
•
Although Dr. Dabees represented the City of Marco Island at the charr•ette, he participated in
discussions regarding Clam Pass & Clam Bay.
•
Dr. Dabees will provide feedback to the USACE as solutions are considered and pursued,
going forward. He suggested that the installation of gates and/or walls in Clam Pass/Clam
Bay would result in significant environmental impacts, and therefore, not recommended.
Environmental impacts must be considered for any proposed projects.
•
The USACE's goal is to complete a draft report by year end and complete a final report of
recommendations by 2025.
•
The USACE study and report are 100% federally funded. The execution of any recommended
projects would be 65% federally funded and 35% County funded.
Ms. McLaughlin commented that going forward, the PBSD's role will be to educate ourselves,
communicate with our representative Mr. Mason, and provide communication to our community.
UPDATE ON CLAM BAY TIDE GAUGES
2
Pelican Bay Services Division Clam Bay Committee Meeting
May 2, 2023
Dr. Dabees reported that one tide gauge was successfully installed in March, and the other
three were installed in April. He noted that the gauges are not transmitting continuous data. Dr.
Dabees will reach out to Locher Environmental (the system host) to have these software glitches
rectified. Dr. Dabees commented that Clam Pass currently looks good and is flushing properly. He
provided a recent photo of the Pass to the committee.
LAST WEEKEND'S STORM
Dr. Dabees reported that last weekend's storm had sustained wind and waves for two
continuous days, with 3-4 foot waves and a two -foot storm surge. Mr. Coleman reported that the surge
caused water to go over the County's newly installed berm, and that all of the newly installed sand at
Marker 36 has been wiped out. He commented that the County has not made a decision on what action
will be taken regarding the loss of their project's sand. Dr. Dabees expressed concerns on the lack of
sufficient slope adjacent to the newly constructed berm. He commented that in the next 24 hours, he
will make a site visit to assess the storm damage, and then make appropriate recommendations.
The meeting was adjourned at 2:17
Denise McLaughlin, Chaii•
Minutes approved [] as presented OR [] as amended ON ( ] date
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Agenda Item #7
Page 1 of 20
2022 CLAM BAY
WATER QUALITY ANALYSIS
Water Quality Analysis for Evaluation of
Limit with Numeric Nutrient Criteria
SECTIONS 4/5/9/32/32, TOWNSHIPS 48/49 SOUTH,
RANGE 25 EAST
COLLIER COUNTY. FLORIDA
Prepared For:
Pelican Bay Services Division
PELICAN c/o Lisa Jacob
®BAY 801 Laurel Oak Drive, Suite 302
Naples, FL 34108
Prepared By:
Earth Tech Environmental, LLC
10600 Jolea Avenue
Bonita Springs, FL 34135
EARTH TECH 239.304.0030
ENVIRONMENTAL
www.eteflorida.com
September 18, 2023
1.0 EXECUTIVE SUMMARY ....................................................
Agenda Item #7
Page 2 of 20
2022 Clam Bay Water Quality Analysis
.................................................... 3
2.0
LIMITATIONS AND EXCEPTIONS............................................................................................................3
3.0
BACKGROUND.......................................................................................................................................4
4.0
SITE DESCRIPTION.................................................................................................................................5
5.0
METHODOLOGY....................................................................................................................................6
5A
Total Phosphorus (TP) & Total Nitrogen (TN).......................................................................................
6
5.2
Dissolved Oxygen Saturation(DOj........................................................................................................6
5.3
Copper (Cu)..........................................................................................................................................a
6
5.4
Chlorophyll-a.........................................................................................................................................6
6.0
RESULTS.................................................................................................................................................7
6.1
Total Phosphorus & Total Nitrogen.......................................................................................................7
6.2
Dissolved Oxygen Saturation..............................................................................................................14
6.4
Copper ............................... ...........................................................................................I.I.......I............16
6.5
Chlorophyll-a.......................................................................................................................................18
7.0
DISCUSSION & RECOMMENDATIONS.................................................................................................20
8.0
REFERENCES........................................................................................................................................21
EXHIBITS
Figure 1
Site Location Map
Figure 2
Water Sample Locations Map
Figure 3
Total Phosphorus Concentrations
Figure 4
Total Nitrogen Concentrations
Figure 5
Dissolved Oxygen Saturation Values
Figure 6
Copper Saturation Values
Figure 7
Chlorophyll -a Values
Figure 8
Relationship Between Total Phosphorus
and Total Nitrogen
Figure 9
Relationship Between Total Phosphorus
and Dissolved Oxygen Saturation
Figure 10
Relationship Between Total Phosphorus
and Chlorophyll -a
TABLES
Table 1 Total Phosphorus Concentrations
Table 2 Total Nitrogen Concentrations
Table 3 Dissolved Oxygen Saturation Values
Table Copper Values
Table 5 Chlorophyll -a Values
APPENDICES
Appendix A 2021 Clam Bay Water Quality Analysis Report (Stantec)
LLC www.eteflorida.com
Agenda Item #7
Page 3 of 20
2022 clam Bay Water Quality Analysis
1,0 EXECUTIVE SUMMARY
Earth Tech Environmental (ETE) conducted data analysis of water quality samples taken from nine (9) pre-
established locations within the Clam Bay Natural Resources Protection Area (NRPA), hereafter referred
to as Clam Bay, Clam Bay is located in coastal Naples, Florida in Collier County, and is comprised of
approximately 560 acres of estuary, mangrove forest, and hand dug channels with connectivity to the Gulf
of Mexico via Clam Pass. See Figure 1 for a location map.
Water quality data for Clam Bay was collected by Collier County Pollution Control (CCPC) and reported
through the Florida Department of Environmental Protection's (FDEP) Watershed Information Network
(WIN) from January through December 2022. Water quality data results were analyzed individually and
reported for overall compliance with site -specific Numeric Nutrient Criteria (NNC) for the following five
analytes: Total Nitrogen (TN), Total Phosphorus (TP), Dissolved Oxygen Saturation (DO), Copper (Cu) and
Chlorophyll -a.
Water quality data obtained over the duration of January through December 2022 indicated that Clam
By was out of compliance for the following analytes: Total Phosphorus, Total Nitrogen, Dissolved Oxygen
Saturation and Chlorophyll -a, based on limits set by the FDEP. Copper, which was banned in the City of
Naples in November 2009, was within compliance. To be in compliance, no morethan 10%of samples can
exceed limits set by FDEP's NNC.
Total Phosphorus levels exceeded the NNC in 43/107 (40%) of samples collected. Data and prior reports
show that Total Phosphorus levels have been consistently out of compliance overthe last eight years.
Total Nitrogen levels exceeded the NNC in 17/107 (16%) of samples collected.
Dissolved Oxygen Saturation levels exceeded the NNC in 24/108 (22%) of samples collected.
Copper was out of compliance for 5/108 (0.05%) of samples collected.
Chlorophyll -a levels exceeded the NNC in 36/108 (33%) of samples collected.
2.0 LIMITATIONS AND EXCEPTIONS
This report is expressly for the sole and exclusive use of the party for whom this report was originally
prepared for a particular purpose. Only the party for whom this report was originally prepared and/or
other specifically named parties have the right to make use of and rely upon this report. Reuse of this
report Crary portion thereof for otherthan its intended purpose, or if modified, or if used by third parties,
shall be at the user's sole risk. Past analysis was used for reference and not prepared or re-evaluated by
ETE for the purpose of this report.
Earth Tech Environmental, LLC
G
Figure 1. Site Location Map
3.0 BACKGROUND
Agenda Item #7
Page 4 of 20
2022 Clam Bay Water Quality Analysis
The 2021 Clam Bay Water Quality Analysis report was prepared by Stantec, and previous reports were
prepared by other entities; data presented in this 2022 report is compared to data analyzed by others and
has not been re-evaluated by ETE. The 2021 report is included in Appendix A for reference. Pelican Bay
Services Division (PBSD) Municipal Services Taxing & Benefit Unit was formed in part to provide water
management, beach renourishment, beautification of recreation facilities, and the maintenance of
conservation preserve areas. PBSD is responsible for advising Collier County on dredging and maintaining
Clam Pass to ensure the health of the mangrove forest and estuary. Water quality may be affected by
environmental factors such as storm activity and tidal influence, in addition to anthropogenic factors such
as dredging and construction activities.
The U.S. Environmental Protection Agency (EPA) adopted nutrient concentration criteria for Clam Bay in
2011, which were also reviewed and approved by the FDEP. Clam Bay has been assigned NNCs that are
termed Site -Specific Alternative Criteria (SSAC), as listed in Chapter 62-302,500 of the Florida
Administrative Code (F.A.C).
The criteria developed for TP and TN depend on salinity and specific conductivity, since analyte
concentrations in saltwatersystems varywith dynamicfactors such as rainfall, runoff, and tidal influence.
In addition to considering salinity and specific conductivity of waters when evaluating whether specific
analytes meet NNC, the analysis also considers the frequency with which analyte concentrations exceed
NNC values, as well as the amount of time over which exceedances have occurred for the 2022 calendar
year. This information may be used to help determine management responses. Clam Bay experienced a
few major disturbances in 2022 including the dredging of Clam Pass in February through April 2022 and
Hurricane Ian on September 28, 2022, which brought 8-10 feet of storm surge into Clam Bay.
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Agenda Item #7
Page 6 of 20
2022 Clam Bay Water Quality Analysis
5.0 METHODOLOGY
Water quality samples were collected by Collier County Pollution Control and analyzed by Collier County
Pollution Control Laboratory for 17 analytes at nine sample locations within Clam Bay. Samples were
collected once monthly over the 2022 calendar year. The 17 analytes included: Ammonia, Chlorophyll -a,
Copper (Cu), Nitrate -Nitrite, Nitrite, Nitrogen- Total Kjeldahl (TN), Orthophosphate (P), Pheophytin a,
Phosphorus- Total (TP), Dissolved Oxygen, Dissolved Oxygen Saturation (DO), pH, Salinity, Specific
Conductance, Water Temperature, Depth- Secchl Disk Depth, and Turbidity. All results were obtained
from WIN, including analytes that are known indicators in declaring a waterbody impaired or out of
compliance by EPA. Discussed below are the results for the 2022 calendar year, which specifically focus
oIn Total Phosphorus, Total Nitrogen, Dissolved Oxygen Saturation, Copper, and Chlorophyll -a. Results
have been calculated and displayed below as pass/fail.
5.1 Total Phosphorus (TP) &Total Nitrogen (TN)
As outlined in 62-302.531 F.A.C., "the water quality status of Total Nitrogen and Total Phosphorus is
determined on an annual basis, preferably within a calendar year, based on Specific Conductivity as a
dynamic qualifier." To determine concentration, samples are collected via a grab bottle and then diluted
and run through a gas chromatographerto read concentration levels. Results arethen calculated persite
as the limits are dependent on many factors such as the relationship between nutrients and salinity, tide,
rainfall, and temperature. These factors are used to determine if the waters of Clam Bay are within
compliance or not. The frequency and duration in which values exceed NNC is considered when
determining appropriate management responses. The specific limits for each sampling location are
calculated according to 62-302-532 F.A.C.:
"No more than 10 percent of the individual Total Phosphorus (TPJ or Total
Nitrogen INJ measurements shall exceed the respective TP Upper Limit or
TN Upper Limit."
Equation 1:
TP
Upper
Limit(mg/L)
= et-1.o62se-o.000032eaas•conda�twlryl�ll
Equation 2:
TN
Upper
Limit(mg/L)
= 2.3601-0.000026R325*Conductivity(µS)
5.2 Dissolved Oxygen Saturation (DO)
The amount of oxygen that can be dissolved in water is dependent on several factors, including water
temperature, salinity, and atmospheric pressure. Dissolved Oxygen Saturation is recorded in the field in
real time using a specialized meter that records dissolved oxygen, temperature, salinity, and atmospheric
pressure. DO shall not fall below 42%saturation in more than 10 percent of the values over the calendar
year as stated in 62-302.533 F.A.C.
5.3 Copper (Cu)
Copper is an essential nutrient at low concentrations but is toxic to aquatic organisms at higher
concentrations. A 2006 National Oceanic and Atmospheric Administration study (NOAA) suggests that
higher Cu concentrations may be acutely toxic for some fish species and are lethal for most invertebrates;
following this, the Florida Department of Agriculture and Consumer Services banned such uses of copper
sulfate in the City of Naples in November of 2009, The limit for Copper has been set to not exceed 3.7
ug/L in compliance with 62-302-530 F.A.C.
5.4 Chlorophyll -a
Chlorophyll -a is a measure of the amount of algae and phytoplankton growing in a waterbody; too much
can cause algae blooms. Such blooms block light from penetrating the surface water and reduce water
Earth Tech
Environmental, LLC
www.eteflorida.com
6
Agenda Item #7
Page 7 of 20
2022 Clam Bay Water Quality Analysis
clarity. Die -offs of these blooms cause large amounts of carbon dioxide to enter the water system and
decrease available oxygen. In accordance with 62-302.531 F.A.C., levels of Chlorophyll -a are not to exceed
11 ug/L.
6.0 RESULTS
Below is a discussion of results based on these set parameters and calculations. Comparisons and
correlations, if any, between TP and Chlorophyll -a. TP and TN, and any effect of TP on DO, are also
provided.
6.1 Total Phosphorus &Total Nitrogen
Total Phosphorus levels are out of compliance for 43/107 (40%) of samples collected and Total Nitrogen
levels are out of compliance for 17/107 (16%) samples. Total Phosphorous increased at the northern sites
in April and May 2022, and again at all of the sites in October 2022 following Hurricane Ian, Total Nitrogen
increased at all sites January— March 2022, and again at 8/9 sample locations in October 2022. Nitrogen
and Phosphorus are essential nutrients In the life cycles of plants and animals. However, when in excess,
may cause an explosion in growth of nuisance plants and algae blooms, reducing water clarity and blocking
Iightfrom reaching below the surface to seagrass beds. The excess algae and plant matter eventually
decompose, producing substantial amounts of carbon dioxide. Phosphorus and Nitrogen enter waterways
from rain runoff of human and animal waste, laundry and cleaning wastewater, industrial effluents, and
fertilizer runoff. Soil erosion is also a major contributor of nutrients into waterways.
The following figures depict results of Total Phosphorous and Total Nitrogen at each sample location.
Table 1. Total Phosphorus concentrations per sample location from March 2015 through December
2022 in Clam Bay.
Green represents samples in compliance with the NNC. Red cells indicate exceedance of the NNC. Red cells
with an 'X" represent values that are within 5% of NNC concentration, suggesting lack of compliance
should be interpreted with caution, due to analytical precision. Gray cells represent lack of data.
TABLE 1. Total Phosphorous (TP) (mg/L) -"
Date Sample Location
(month/year) CBl
CB2
CB3
CB4
CB5
CB6
CB7
C68
CB9
Mar-15
Mar-15
Apr-15
May-15
X
lun-15
Jul-15
Aug-15
Sep-15
OM-15
Nov-15
X
Dec-15
Jan-16
Feb-16
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Agenda Item #7
Page 8 of 20
2022 Clam Bay Water Quality Analysis
Mar-16
Apr-16
May-16
Jun-16
Jul-16
Aug-16
Sep-16
Oct-16
Nov-16
Dec-16
Jan-17
Feb-17
Mar-17
X
Apr-17
May-17
X
Jun-17
Jul-17
Aug-17
Sep-17
Oct-17
Nov-17
Dec-17
Jan-18
Feb-18
Mar-18
X
X
Apr-18
X
May-18
X
Jun-18
Jul-18
Aug-18
Sep-18
Oct-18
Nov-18
Dec-18
Jan-19
Feb-19
9
X
9999999
j
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Agenda Item #7
Page 9 of 20
2022 Clam Bay Water Quality Analysis
Dec-19
Jan-20
Feb-20
Mar-20
RIM
Apr-20
May-20
Jun-20
Jul-20
x
Aug-20
Sep-20
OM-20
Nov-20
Dec-20
Jan-21
X
Feb-21
Mar-21
X
x
x
Apr-21
May-21
Jun-21
X
x
x
X
Jul-21
Aug-21
Sep-21
Oct-21
Nov-21
Dec-21
Jan-22 79
0.073
0.059
0.048
0.046
0.052
0.033
0.034
0.053
Feb-22 16
0.076
0.058
0.043
0.046
0.052
0.059
0.058
0.065
Mar-22 02
0.125
0,127
0-11
0-099
0.101
0.12
0.084
0.089
Apr-22 13
0.102
0.098
0.035
0.041
0.069
0-092
0.078
0.081
May-22 64
0 M
0.098
0.096
0.054
0.044
0.064
0.057
0.062
Jun-22 .1
0.09
0.07
0.061
0.047
0.046
0.054
0.043
0.057
July-22 086
0.059
0.054
0.067
0.038
0.044
0.051
0.058
0.11
Aug-22 .08
0,06
0.05
0.044
0.041
0.036
0.06
0.054
0.045
Sep-22 076
0.039
0.037
0.037
0.029
0.041
0.043
0.051
0.047
Oct-22 66
0.108
0.094
0-067
0.05
0.056
0.049
0.061
0.071
Nov-22 -.61
0.181
n/a
0,096
0.082
0.063
0.071
0.078
0.057
Dec-22 55
0.141
0.101
0.115
0-085
0.096
(H
0.D81
0.131
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Agenda Item#7
Page 10 of 20
2022 Clam Bay Water Quality Analysis
Figure 3. Total Phosphorous concentrations per sample location over the period of January 2022
through December 2022 in Clam Bay,
0.3
0.25
m
0.2
0
a
0.15
0
a
0.1
F�-
0.05
C
Total Phosphorus(TP)
1 2 3 4 S 6 7 8 9 10 11 12
Month
t CB1
C82
C83
C84
t- CB5
F C86
t C87
t CB8
—�—CB9
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Agenda Item #7
Page 11 of 20
2022 Clam Bay Water Quality Analysis
Table 2. Total Nitrogen concentrations per sample location from March 2015 through December 2022
in Clam Bay.
Green represents samples in compliance with the NNC. Red indicates exceedance of the NNC. Red cells
with an 'X" represent values that are within 5% of NNC concentration, suggesting lack of compliance
should be interpreted with caution, due to analytical precision. Gray cells represent lack of data.
TABLE 2. Total Nitrogen (TN) (mg/L)
Date Sample Location
(month/year) CBl
CB2
CB3
CB4
CBS
CB6
CB7
CB8
CB9
Mar-15
Mar-15
Apr-15
May-15
`
Jun-15
Jul-15
Aug-15
Sep-15
;A
--
Oct-15
Nov-15
Dec-15
Jan-16
Feb-16
Mar-16
Apr-16
May-16
Jun-16
Jul-16
Aug-16
Sep-16
Oct-16
Nov-16
Dec-16
Jan-17
Feb-17
Mar-17
Apr-17
May-17
Jun-17
Jul-17
Aug-17
Sep-17
Oct-17
Nov-17
Earth Tech Environmental, LLC
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Agenda Item #7
Page 12 of 20
2022 Clam Bay Water quality An@lysls
Earth Tech
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12
Agenda Item #7
Page 13 of 20
2022 Clam Bay Water quality Analysis
Sep-21
Oct-21
Nov-21
Dec-21
Jan-22 0.724
0.748
0.596
0.687
0.729
0.704
0.539
0.533
0.668
0.512
Feb-22 1.03
0.706
0.78/
0.815
0.868
0.851
i..07.
0.809
Mar-22 1.22
1.05
1.11
1.12
1
1.06
3.32
0.922
0.973
Apr-22
0.937
0.973
0.691
0.639
0.782
0.975
1.05
0.926
May-22
1.08
0.974
0.833
0.811
0.707
0.756
0.825
0.8
Jun-22
1.1
0.688
0.645
0.616
0.749
0.739
0.685
0.587
Jul-22 0.928
0.666
0.624
0.675
0.554
0.584
0,543
0.565
0.547
Aug-22 1.33
0.865
1.07
0.67
0.797
0.826
0.922
0.88
0.847
Sep-22 1.05
0.81
0.688
0.854
0.673
0.746
0.839
1.19
0.812
Oct-22 19
1.11
1.06
1.64
0.799
0.845
0.9
0.771
0.959
Nov-22
Dec-22
0.895
0.876
0
•-6
Figure 4. Total Nitrogen
concentrations
per sample
location over the period of January 2022 through
December 2022 in Clam
Bay,
z
1.8
1.6
1.4
E
1.2
c
w
0
1
z
0.8
F
0.6
0.4
0.2
0
1
Total Nitrogen (TN)
2 3 4 5 6 7 8 9 10 11 12
Month
+CB1
CB2
CB3
CB4
t CBS
-�-CB6
�-CB7
f CB8
-1-C89
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Agenda Item #7
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2022 Clam Bay Water quality Analysis
6.2 Dissolved Oxygen Saturation
Dissolved Oxygen Saturation is out of compliance in 24/108 (22%) samples collected. DO dropped across
most of the sample sites in January -August 2022, with slight increases in July, and increased during the
last few months of the year. DO is measure of how much oxygen is dissolved in the water and
consequently the amount of oxygen available to living aquatic organisms. Dissolved Oxygen Saturation is
one of the most vital indicators of water quality as it determines not only the quantity of species, but
diversity of species able to thrive. Human sources of oxygen -depleting organic materials include
stormwater runoff, and/or failing septic systems (NOAA). The following tables and figures depict findings
for compliance of DO at each sample location.
Table 3. Dissolved Oxygen Saturation values per sample location over the period of January 2021 to
December 2022 in Clam Bay in relation to the established standard criteria for Class II waters (42%
saturation).
Green represents samples in compliance with criteria. Red cells are below the established standard criteria.
TABLE 3. Dissolved Oxygen Saturation
Date Station Location
(month/year) CB1
C62
CB3
CB4
CBS
CB6
CB7
CB8
CB9
Jan-21 ..4
61
57.8
80.1-.
98.4
90.9
50
lan-21
61.4
80.4
76.8
83.784
82.6
84.9
Feb-21
60.9
76.2
79.3
87
89.1
91.9
80
Mar-21
40.1
51.8
74
81.1
83.1
77.9
71.4
Apr-21
40
32.8
62..5
63.1
76.3
90.3
96.7
93.7
ay-21
43.9
83.1
94.5
84.2
91.1
81.4
ne-21 .3
337
66.7
53.6
74.6
85.8
77.9
92.9
ly-21
j
10
21.6
42.6
63.2
75
69.3
72.4
g-21
6.3
26.6
40.3
27.2
44.5
789
887
74.5
71.9
53.8
p-21
29.6
61.1
782
78.8
Oct-21
26
52.2
57.2
75.1
91.9
88.3
73.6
Nov-21 6
51.2
55.4
62.7
105.4
98.8
108.3
97.3
78.3
Dec-21
44.2
56.8
61.6
71.7
85
85.2
Jan-22 6
$6.4
58.9
61..7
86.9
96.6
94.7
89.8
Feb-22
44.6
65.4
75.9
76.2
94
97
11L6
Mar-22 2
25.9
69.3
38.1
52.2
90.7
92
80.9
Apr-22
50.6
65.9
85.9
78.6
93.6
95.2
89
May-22
26
57
51.5
64.1
84.1
85.4
78.4
Jun-22
20.4
34.5
46.1
66.3
73.5
78.1
74.9
Jul-22
40.9
60.1
67.5
75.6
65
76.2
82.6
Aug-22
23.8
64.4
62.7
77.8
80
72.7
70.9
CY
Sep-22
34.7
8.6
56.1
53.2
67.3
95.5
79.4
55.6
85.8
72.8
72.4
Oct-22
17.6
28.7
72.3
82.9
Nov-22 -5
Dec-22
129
42.7
23.8
55.5
1 55.1
69.5
82.7
98.2
93.5
119.2
85.9
107.4
f
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Agenda Item #7
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2022 Clam Bay Water Quality Analysis
Figure 5. Dissolved Oxygen Saturation values per sample location over the period of January 2022
through December 2022 in Clam Bay,
Dissolved Oxygen (DO)
Lower Limit: 42%
140
120
e
�
100
o_
80
v
60
c
m
40
x
O
20
0 i �
1 2 3 4 5 6 7 8 9 10 11 12
Month
t CB1
�CB2
J. --CB3
CB4
+CB5
t C66
tC67
tC88
—�—C89
Limit
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Agenda Item #7
Page 16 of 20
2022 Clam Bay Water Quality Analysis
6.4 Copper
Copper is out of compliance in 5/108 (0.05%) samples collected, primarily at CB1 from June to September
2022. Chronic Copper above 3.7 ug/L exposure can adversely affect fish health including damage to gills,
liver, kidney, immune system, and nervous system. Prolonged copper exposure also may result in reduced
fish growth and eventually death (Wong et al. 2018).
According to NOAA, natural sources of Copper In aquatic systems Include weathering and erosion of rocks
and soils. Anthropogenic sources of Copper include pesticide use and algaecides. A majorsource of Copper
in the marine environment is antifouling paints, used as coatings for ship hulls, buoys, and underwater
surfaces, and as a contaminant from decking and pilings.
Table 4. Copper values per sample location over the period of January 2021 through December 2022 in
Clam Bay in relation to the established standard criteria for Class II waters (3.7 ug/ Q.
Green represents samples in compliance with criteria. Red cells are above the established standard criteria.
TABLE 4. Copper (µg/L)
Sample Location
Date CB1
(month/year)
CB2
CB3
CB4
CBS
CB6
CB7
CB8
CB9
Jan-21 29
Feb-21 3.5
9-
2.1.3
-�..
...
- 2
3
1.2
151
-.
3.05
1.82
1.2
1..2
1.32
Mar-21 2.43
6.38
2.24
1.2
L2
1.2
1.2
1.2
Apr-21 .89
3.85
3.02
2.12
1.53
1.81
2.11
3.1
May-21 6.58
5.3
3.69
12
L2
2.05
Z57
254
June-21 3.04
2.79
2.18
1.75
1.67
1..47
2.03
1.65
July-21 2.05
2.35
1.65
1.54
1.13
1.2
1.94
1.05
Aug-21 2.5
1.89
1.4
1.35
1.18
1.05
1.17
1.05
Sep-21 2.38
1.41
L27
0.98
1.05
1.05
1.05
1.05
Oct-21 1.17
1.05
1.05
1.05
1.2
1.35
1.2
1.2
Nov-21 1.59
2.1
1.43
1.45
1.05
1.05
1.16
1.1
Dec-21 1.37
227
2A6
1.44
1.2
12
2.5
1.2 -
Jan-22 2,44
2.68
2.38
2.51
1.2
1.41
1.2
L2
Feb-22 -: 2.37
2.91
2.31
1.93
12
1.32
1.36
L2
Mar-22 45. 16
3.18
5.02
1.9
1.05
2.44
2.21
128
Apr-22 " 2.19
1.72
2.17
1.2
1.2
1.4
1.73
1.2
May-22 2.04
2.91
1.83
1.96
L2
1.2
1.2
1.2
Jun-22 3.16
2.52
1.81
1.49
1.2
1.2
1.2
L2
Jul-22 .17
2.96
2.48
3.38
1.05
1.2
1.2
1.2
Aug-22 .27
2.85
2.05
1.27
1.05
1.2
1.72
1.2
Sep-22 .92
2.85
1.11
1.05
1.2
1.05
1.u5
1.05
Oct-22 1.26
2.44
1.2
1.2
1.05
1.2
1.2
1.2
Nov-22 0.9
L14
LOS
1.05
1.2
1.2
L21
1.29
Dec-22 -
1.05
1.18
1.2
1.2
1.2
1.2
1.2
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2022 Clam Bay Water Quality Analysis
Figure 6. Copper
saturation
values per sample
location over the period of January 2022 through
December 2022 in
Clam Bay.
1a
9
8
7
6
v
5
a
0
4
V
3
2
1
0
1
Copper(Cu)
Upper Limit: 3.7 ug/L
2
3
4
S
6 7
8
9
10
11
12
Month
tcB1
�•CB2
9—CB3
—�—CB4
—HCBS
#—CB6
tC87
�—CB8
t CB9
Limit
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Agenda Item #7
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2022 Clam Bay Water quality Analysis
6.5 Chlorophyll -a
Chlorophyll -a is out of compliance for 36/107 (36%) of samples collected, making Clam Bay impaired for
Chlorophyll -a.
Table 5. Chlorophyll -a values per sample location over the period of January 2022 through December
2022 in Clam Bay. Highlighted values fall below the established standard criteria for Class II waters (11
ug/L).
Green represents samples in compliance with criteria. Red cells indicate exceedance of criteria.
Figure 7. Chlorophyll -a values per sample location over the period of January 2022 through December
2022 in Clam Bay,
50
45
40
35
00
30
S
25
n
0
20
`o
15
10 ,
5 1
0
Chlorophyll -a
Upper Limit: 11 ug/L
1 2 3 4 5 6 7 8 9 10 11 12
Month
—O—CB2
CB3
CB4
t CB5
�—CB6
—C67
—f—CB8
t CB9
Limit
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Agenda Item #7
Page 19 of 20
2022 Clam Bay Water quality Analysis
The following analysis shows that Total Phosphorus has a direct correlation on increases in Chlorophyll -a
and Total Nitrogen, triggering these analytes to also increase. Total Phosphorus also has an inverse
correlation on Dissolved Oxygen Saturation; reducing the amount of oxygen, increasing eutrophication,
dead zones (hypoxia) and decreasing pH (ocean acidification).
Figure 8. Direct relationship between Total Phosphorus and Total Nitrogen over the period of January
2022 through December 2022 in Clam Bay.
Total Phosphorous vs. Total Nigrogen
z
1.8 •
1.6 • R2 = 0.5463•••
m
• • ...*...
1.2 • • • ....�.....• •
0 1
z 0.8 • % �'�♦.•�....••
•
00
...
0.4
0.2
0 --
0 0.05 0.1 0.15 0.2 0,25 0.3
Total Phosphorous (mg/L)
Figure 9. Inverse relationship between Total Phosphorus and Dissolved Oxygen Saturation over the
period of January 2022 through December 2022 in Clam Bay,
Total Phosphorous vs. Dissolved Oxygen Saturation
120
0 100 • • /• • •
m 80 • , �• �• • •
,m 60 , •..r..+.. •
40
Ox • "••.......,•
v 20 • •� M••• • • o • • : .............••
o
0.05 0;1 0,15 0.2 0.25 '•'
-20
Total Phosphorous (mg/L.)
0.3
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Agenda Item #7
Page 20 of 20
2022 Clam Bay Water Quality Analysis
Figure 10. Direct relationship between Total Phosphorus and Chlorophyll -a over the period of January
2022 through December 2022 in Clam Bay.
Total Phosphorous vs. Chlorophyll -a
50
45 •
40 •
'Q 35 •
; 30 •• • R2=0.29.17..••
a 25 • •
0 20 • • • •
15 �• 1,f..............
U •
10 • •N S� • ••.
5 001 •• •
4i••i •
0 0.05 0.1 0.15 0.2 0.25
Total Phosphorous (mg/L)
7.0 DISCUSSION &RECOMMENDATIONS
0.3
Total Phosphorus
Total Phosphorus levels exceeded the NNC in 43/107 (40%) of samples collected. Data and prior reports
show that Total Phosphorus levels have been consistently out of compliance over the last eight years.
Total Nitrogen
Total Nitrogen levels exceeded the NNC in 17/107 (1676) of samples collected.
Dissolved Oxygen Saturation
Dissolved Oxygen Saturation levels exceeded the NNC in 24/108 (22%) of samples collected.
Copper
Copper is out of compliance in 5/108 (0.05%) of samples collected.
Chlorophyll -a
Chlorophyll -a levels exceeded the NNC in 36/108 (33%) of samples collected.
Clam Bay experienced a few major disturbances in 2022 including the dredging of Clam Pass (February
through April 2022) and Hurricane Ian on September 28, 2022, which brought 8-10 feet of storm surge
into Clam Bay. These events potentially contributed to increased nutrient loads and decreased dissolved
oxygen levels by stirring up sediments. These major disturbances make it difficult to pinpoint definitive
causes of exceedances, especially for Total Phosphorus and Total Nitrogen. Additional testing including
sediment sampling or comparisons to berm outfalls may be beneficial to more acutely pinpoint potential
causes and duration of elevated nutrient levels and decreased Dissolved Oxygen.
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