Pequonnock River Trumbull July through October 2014

Water Quality Report
For
The Pequonnock River in Trumbull
July 2014 through October 2014
Looking upstream the Pequonnock River in Old Mine Park
Submitted By:
Richard Harris, Principle Investigator, Staff Scientist/Director of the Harbor Watch Program at
Earthplace, Westport, CT Phone: 203-227-7253
Peter Fraboni, Associate Director & QA/QC Officer for the Harbor Watch Program at Earthplace,
Westport, CT
Nicole Cantatore, Laboratory Director of Harbor Watch Auxiliary Laboratory
Joshua Cooper, Coastal Studies Technician and Quality Assurance Officer of Harbor Watch, A Program
of Earthplace Westport, CT
Funding for this study was provided by the Town of Trumbull Engineering Department
Table of Contents
Pg.
Introduction
Methods and Procedures
Results
Discussion
References
Appendix A
3
3
5
8
10
11
List of Figures and Tables
Pg.
Figure 1
Map of the Trumbull Section of the Pequonnock River showing the location of the ten
monitoring sites
4
Figure 2
Observed maximum, geomean, and minimum E. coli values for the ten monitoring
sites and one storm drain site in the Trumbull section of the Pequonnock River
Watershed
Dissolved oxygen maximum, mean, and minimum concentrations for ten monitoring
sites and one storm drain site in the Trumbull section of the Pequonnock River
Watershed
Conductivity maximum, mean, and minimum values for ten monitoring sites and one
storm drain site in the Trumbull section of the Pequonnock River Watershed
Mean water temperatures (oC) for the ten monitoring sites and one storm drain site in
the Trumbull section of the Pequonnock River Watershed
6
Monitoring site numbers and GPS coordinates in the Trumbull Section of the
Pequonnock River
CT DEEP criterion for E. coli bacteria levels as applied to recreational use, effective
2/25/11
Observed E. coli counts on each sampling event (six total) geometric means, rainfall
amounts, and % frequency exceeding 576CFU/100mLs for each monitoring site in the
Trumbull section of the Pequonnock River Watershed
Conductivity (uS) maximum, mean, minimum, and range values for ten monitoring
sites and one storm drain site in the Trumbull section of the Pequonnock River
Watershed
5
Figure 3
Figure 4
Figure 5
Table 1
Table 2
Table 3
Table 4
7
7
8
5
6
8
Introduction
A Memorandum of Understanding (MOU) agreement between the Engineering Department of the Town
of Trumbull, CT and the Earthplace Harbor Watch (HW) Water Quality Monitoring Program was made to
have HW conduct a study of indicator bacteria (Escherichia coli, E. coli) levels, dissolved oxygen (DO),
conductivity, and water temperatures in the Trumbull section of the Pequonnock River Watershed. In
2009 and 2010 the Connecticut Department of Energy and Environmental Protection (CT DEEP)
contracted HW to conduct a survey of the entire Pequonnock River from Monroe through Trumbull and
Bridgeport to gather data on indicator bacteria, DO, conductivity, and water temperatures. Two of the
original ten total sites were situated in the Trumbull section of the Pequonnock River. For this study eight
(8) more monitoring sites were chosen, and added to the two established sites that were tested in the 2009
and 2010 study (Figure 1and Table 1).
The Pequonnock River watershed, which begins in Monroe, encompasses an area of over 15,000 acres in
the southwestern Connecticut. The river is 16.7 miles long and flows from Monroe through the Town of
Trumbull and finally into Bridgeport terminating in the estuary of the Bridgeport Harbor. The river is
slightly over 7 miles in Trumbull. The CT DEEP has divided the main stem of the Pequonnock River
into 5 segments (Water body ID numbers CT7105-00_01, CT7105-00_02, CT7105-00_03, CT710500_04, and CT7105-00_05). One segment CT7105-00_03 (from Daniels Farm Road to Monroe
Turnpike, CT Route 111 at the intersection of CT Route 25) is 4.19 miles, and lies totally within the
boundaries of Trumbull. The segment (CT7105-00_04) to the north of CT7105-00_03 is located partially
in Trumbull and is approximately 0.9 miles in length. Segment CT7105-00_02 lies to the south of
Segment CT7105-00_03 and is partially in Trumbull and Bridgeport. The river in the Trumbull portion
of this segment is approximately 2 miles of the 2.92 of the total segment’s length. The west branch of the
Pequonnock River (CT7105-01_01) is 1.51 miles in length, and is located entirely in the Town of Monroe
(CT DEEP 2012).
Because previous monitoring conducted by the Earthplace HW Program for the CT DEEP documented
elevated indicator bacteria levels in approximately 80% of the Pequonnock River (Fuss & O’Neill 2011),
The Trumbull Engineering Department wanted to know what the current water quality conditions were in
the Trumbull section of the Pequonnock River. In 2013 the HW Program with support from CT DEEP
604(b) program initiated a three year study of ten sampling sites in the Monroe (northern) section of the
Pequonnock River. The 2014 study of the Trumbull section will complement data collected in the
Monroe section of the Pequonnock River during the same testing interval.
Methods and Procedures
Water monitoring was conducted following testing protocols in Quality Assurance Project Plan (QAPP)
for the Pequonnock River Watershed (RFA#13058). The QAPP was approved by CT DEEP and EPA on
5/6/13 and is effect for three years. Monitoring teams leave Earthplace in Westport to gather in situ data
on dissolved oxygen, conductivity and water temperature in the Trumbull section of the Pequonnock
River. Water samples are collected at each of the ten monitoring sites (Figure 1) along the length of the
river for the analysis of indicator bacteria.
The following tests are run in situ: dissolved oxygen (QAPP Appendix A3.2) and conductivity (QAPP
Appendix A3.3). Water and air temperatures, as well as general observations and storm events are also
recorded at each site visit. Observations are recorded (QAPP Appendix 5) on the HW data sheet.
Upon return to the lab, fecal coliform bacteria membrane filtration tests (QAPP Appendix A3.5) are
performed and E. coli testing is carried out according to Standard Methods, 22nd edition (9222D &
9222G) and recorded (QAPP Appendix 5) on the HW bacteria log. During the monitoring period, sites
were monitored twice per month.
Figure 1 Map of the Trumbull Section of the Pequonnock River showing the location of the ten
monitoring sites
Table 1 Monitoring site numbers and GPS coordinates in the Trumbull Section of the Pequonnock River
Sampling
Sites
PQ7.1
PQ7
PQ6.5
PQ6.4
PQ6.3
PQ6.2
Latitude
Longitude
41.29294
41.29381
41.28725
41.28069
41.28025
41.25469
-73.2548
-73.2407
-73.2284
-73.2217
-73.2183
-73.2071
PQ6.1
41.25061
-73.2051
PQ6
41.24681
-73.1971
PQ5.9
PQ5.8
41.23356
41.22878
-73.1839
-73.1811
Comments
Site on North Farrar Brook on Coventry Lane
Site on Spring Hill Road off the bridge
Site in Old Mine Park
Site on Whitney Avenue off bridge near Riverside Drive
Site in Indian Ledge Park
Site in Indian Ledge State Park
Site flowing into the Pequonnock from a storm drain
outfall
Site where the Pequonnock crosses on Daniels Farm
Road bridge
Site within Unity Park
Site at the end of Cottage Place
E. coli bacteria will be evaluated using the criteria published in the CT DEEP Surface Water Quality
Standards, 2/25/11. The CT DEEP E. coli criterion for Class AA, A, and B water is established at three
levels (Table 2).
The Pequonnock River is classified for “all other recreational uses” because the public does not bathe in
or drink the river water, and because it is too shallow for swimming. The report will focus on E. coli
bacteria levels, because it is the indicator bacteria of choice by the CT DEEP.
Table 2 CT DEEP criterion for E. coli bacteria levels as applied to recreational use, effective 2/25/11
Designated Use
Recreation
Designated
Swimming
Class
Indicator
Non-designated
Swimming
AA, A, Escherichia
B
coli
AA, A, Escherichia
B
coli
All
Other AA, A, Escherichia
Recreational Uses
B
coli
Criteria
Geometric Mean less than
126/100; Single Sample
Maximum 235/100
Geometric Mean less than
126/100; Single Sample
Maximum 410/100
Geometric Mean less than
126/100; Single Sample
Maximum 576/100
Results
Indicator bacteria (E. coli) levels for the 10 monitoring sites (and one storm drain pipe) are contained in
Table 3 and Figure 2. Two monitoring sites, PQ 6.1(396 CFUs/100 mLs) and PQ 5.8 (153 CFUs/100
mLs) had geometric mean levels of E. coli bacteria that exceeded the CT DEEP geometric mean criterion
(<126 CFUs/100 mLs) for a Class B river. Site PQ 6.1 also exceeded the Single Sample Maximum
(SSM, <576 CFUs/100 mLs) criterion on two of the five sampling events during the study period. Sites
PQ 6.5, PQ2, PQ6 and PQ 5.8 also exceeded the SSM once on the first sampling event (7/16/2014).
Table 3 Observed E. coli counts on each sampling event (six total) geometric means, rainfall amounts,
and % frequency exceeding 576 CFU/100mLs for each monitoring site in the Trumbull section
of the Pequonnock River Watershed
%frequency
over 576
Sites
7/16/2014 7/30/2014
8/6/2014
10/8/2014 10/22/2014 Geomean CFUs/100 mLs
PQ7.1
88
16
8
52
68
33
0.00%
PQ7
192
20
52
380
12
62
0.00%
PQ7.01
28
440
112
111
0.00%
PQ6.5
920
40
68
540
20
122
20.00%
PQ6.4
70
88
68
60
2
35
0.00%
PQ6.3
360
16
4
124
26
38
0.00%
PQ6.2
660
48
40
56
30
73
20.00%
PQ6.1
1120
350
228
880
124
396
40.00%
PQ6
700
28
92
60
18
72
20.00%
PQ5.9
540
116
88
112
40
120
0.00%
PQ5.8
720
124
80
164
72
153
20.00%
Rainfall (inches) 2.07
0.28
0.48
0.09
0.85
Days Prior
2*
2
3
1
7
*indicates rainfall amounts will additive for that sampling event
Figure 2 Observed maximum, geomean, and minimum E. coli values for the ten monitoring sites and one
storm drain site in the Trumbull section of the Pequonnock River Watershed
E. coli Colonies/100 mLs
10000
1000
a
100
10
1
PQ7.1
PQ7
7.01
PQ6.5
PQ6.4
PQ6.3
PQ6.2
PQ6.1
Sites
Maximum value
a
CT DEEP geometric mean limit for a Class B river
Geomean
Minimum value
PQ6
PQ5.9
PQ5.8
Figure 3 Dissolved oxygen maximum, mean, and minimum concentrations for ten monitoring sites and
one storm drain site in the Trumbull section of the Pequonnock River Watershed
12.0
Dissolved oxygen, mg/L
10.0
8.0
6.0
a
4.0
2.0
0.0
PQ7.1
PQ7
7.01
PQ6.5
PQ6.4
PQ6.3
PQ6.2
PQ6.1
PQ6
PQ5.9
PQ5.8
Sites
Maximum value
a
Mean
Minimum value
CT DEEP minimum criterion for DO for a Class B river
Figure 4 Conductivity maximum, mean, and minimum values for ten monitoring sites and one storm drain
site in the Trumbull section of the Pequonnock River Watershed
2500
Conductivity, uS
2000
1500
1000
500
0
PQ7.1
PQ7
7.01
PQ6.5
Maximum value
PQ6.4
PQ6.3
PQ6.2
Sites
Mean
PQ6.1
Minimum value
PQ6
PQ5.9
PQ5.8
Table 4 Conductivity (uS) maximum, mean, minimum, and range values for ten monitoring sites and one
storm drain site in the Trumbull section of the Pequonnock River Watershed
Site
Max
Mean
Min
Range
PQ7.1
210
184
164
46
PQ7
363
294
233
130
7.01
593
570
557
36
PQ6.5
424
347
276
148
PQ6.4
415
351
284
131
PQ6.3
337
278
212
126
PQ6.2
380
327
271
109
PQ6.1
2290
1835
1159
1131
PQ6
391
338
284
107
PQ5.9
338
295
228
110
Figure 5 Mean water temperatures (oC) for the ten monitoring sites and one storm drain site in the Trumbull
section of the Pequonnock River Watershed
25.0
Water temperature oC
20.0
15.0
10.0
5.0
0.0
PQ7.1
PQ7
7.01
PQ6.5
PQ6.4
PQ6.3
PQ6.2
PQ6.1
PQ6
PQ5.9
PQ5.8
Sites
Dissolved oxygen (DO) concentrations at most of the monitoring sites were well above the CT DEEP
minimum DO criterion of 5 mg/L (Figure 3). Site PQ 7.1, however, on two of the five sampling days
exhibited DO concentrations below the CT DEEP minimum criterion.
Conductivity was lowest at PQ7.1, a site in the northern Trumbull section of the Pequonnock River
watershed near the Monroe Town line, and the highest was observed at Site PQ6.1, an un-named tributary
stream that enters the Pequonnock River Valley State Park to join the main branch of the Pequonnock
River (Figure 4). Site PQ6.1 exhibited remarkably high Conductivity values from 1159 uS to 2290 uS
during the study period. Most of the other monitoring sites except the storm drain site (PQ7.01) had
fairly narrow conductivity ranges from a low of 107 uS to 149 uS (Table 4).
Means of water temperatures for the monitoring sites are displayed in Figure 5. Storm drain site PQ7.01
had the lowest water temperature (16.8 oC), and site PQ5.9 had the highest (22.7 oC). These two sites also
had the lowest (14.8 oC ) and highest (19.1 oC ) mean water temperatures respectively.
Discussion
During the short monitoring period from July 16, 2014 to October 22, 2014 five monitoring events took
place in the Trumbull section of the Pequonnock River from the Monroe Town border to near the
Bridgeport Town line. Indicator bacteria (E. coli) levels were generally the highest on the first sampling
event (July 16, 2014) for most of the sampling when a significant rainfall occurred 2 days prior to
sampling. Most the monitoring sites had geometric means for E.coli bacteria concentrations below 126
CFUs/100 mLs, except for Site PQ6.1 and Site PQ5.8. Several monitoring sites PQ6.5, PQ6.4, PQ6.3,
PQ5.8
381
319
232
149
PQ6.2, and PQ6.1 lie within or in close proximity to open space areas: Old Mine Park and the
Pequonnock Valley State Park. Substantial riparian buffers exist at these monitoring sites and may help
to explain why indicator bacteria levels were for the most part at low concentrations. However, site
PQ6.1 is an exception.
Of the ten sampling sites Site PQ6.1 appeared to have consistently high indicator bacteria levels
exceeding the SSM 40 % of the time. Although this site lies within the Pequonnock Valley State Park, it
receives a substantial water flow to it from the Norwood Terrace neighborhood area outside the park.
This site also had extremely elevated conductivity values, when compared to those of the other
monitoring sites. High E. coli levels and conductivity values may suggest a possible infiltration from a
compromised storm drain or other pollution sources. It may be fruitful to investigate this un-named
tributary for pollution inputs to try and find the cause of high conductivity and elevated indicator bacteria
concentrations. Because site PQ6.1 exhibits a wide conductivity range, it may be greatly affected by
impervious surface runoff, or have an unknown input affecting its water quality.
Although Site PQ6.5 met the geometric mean for E. coli bacteria, it exceeded the 576 CFUs/100 mLs
Single Sample Maximum (SSM) on July 16, 2014 (920 CFUs/100 mLs) and came very close to that level
on October 8, 2014 (540 CFUs/100 mLs). Site PQ6.5 is located in Old Mine Park, so it was surprising
that bacteria counts were elevated on two of the five testing days. On the other three testing days bacteria
levels were very low. More investigation would be needed to see if storm drain infiltration may be
causing these fluctuations.
The lowest E.coli counts were found at site PQ7.1 on Coventry Lane. This site is located on North Farrar
Brook, a tributary located west of the Pequonnock River. During the study period water flow was low at
this site, and no direct storm drain discharges were evident. Good riparian buffers exist here and may be
the reason why indicator bacteria and conductivity levels were low at this site.
The southern Trumbull Pequonnock River monitoring sites (PQ6, PQ5.9, and PQ5.8) were fairly
uniformly low with respect to E. coli single sample concentrations and geometric means. It was
anticipated that E. coli levels would be elevated at site PQ6, because of its in close proximity to
impervious surfaces in the commercial area of White Plains Road. Only on the first sampling day (July
16, 2014) were E. coli counts high, probably due to runoff from a significant rainfall 2 days prior to
sampling. Sites PQ5.9 and PQ5.8 are located in residential neighborhoods having fairly good riparian
buffers although both had high E.coli levels due to the significant rainfall two days prior to sampling.
Most of the Pequonnock River monitoring sites were characterized with rapidly moving water so it was
not surprising that dissolved oxygen (DO) was well above the CT DEEP criterion of 5 mg/L. Only at site
PQ7.1 did DO concentrations fall below the 5 mg/L criterion during two of the five sampling events. The
water at this site on North Farrar Brook can be slow moving during dry periods, so it is understandable
that DO levels could be low here.
Narrow conductivity ranges were observed at most Pequonnock River monitoring sites in the Trumbull
section, which would identify them as stable and not affected greatly by storm water runoff. However,
two sites PQ6.1 and PQ 7.01 stand out with elevated conductivity values. Site PQ7.01 was discovered
on the third sampling event and added to the survey. This site had a low conductivity range, but its mean
was 570 uS. The conductivity appeared to be due to the presence of elevated iron levels. The presence of
iron slime bacteria and the characteristic orange precipitate was observed at the site. Some of this orange
precipitate flowed in to the Pequonnock River, and may have an effect on raising the conductivity
downstream at site PQ7 on Spring Hill Road. It should be noted that booms were deployed downstream
of the Spring Hill Road bridge. Site PQ7 and PQ7.01 are located next to a school bus depot and an
industrial park.
Site PQ6.1 as stated previously stated exhibited extremely high conductivity. Conductivity was 1159 uS
on the first day of sampling and highest 2290 uS on the last day of sampling (October 22, 2014). The
conductivity means (1835 uS) were between 3.3 to 6.4 times higher than that of the other conductivity
means observed at the other main river sites. Because this site also exhibited the highest indicator
bacteria levels, this site warrants further study to understand what may be causing these observations
Water temperatures at the other monitoring sites were fairly consistent. The lowest water temperature was
observed at site PQ7.01 (mean = 14.8 oC). This may be due to the fact that water flowing to this site
travels through an underground pipe. Water temperature was also lower at site PQ6.1 (mean=16.9 oC).
This site also may have water travelling underground and away from the exposure of sunlight.
The general water quality conditions observed during this short study in the Trumbull section of the
Pequonnock River were generally good. Healthy levels of DO exist throughout this section and good
riparian buffers especially where the river passes through parks and open spaces. Most of the monitoring
sites met the CT DEEP geometric mean criterion for indicator bacteria levels (E. coli), but high bacteria
levels and elevated conductivity at site PQ6.1 need to be further investigated. There is a plan to revisit
these same monitoring sites in the spring season (2015), and to add nutrient (especially phosphorous
analysis) testing.
During the period of this study an observation was made at Site PQ7of a boom that was placed across the
river just downstream of the Spring Hill Road Bridge (Appendix A). It would appear that the boom is
collecting flock at the surface. It is not known if this equipment was place temporarily or is a permanent
fixture to protect against pollution runoff from the upstream bus depot.
We wish to acknowledge and thank Frank Smeriglio, Town of Trumbull Engineering Department, for his
support for conducting this survey, as well as the Trumbull Parks and Recreation Department for allowing
vehicular access to the monitoring sites within the Trumbull Town Parks, and to Trumbull Park Ranger,
Mark Ceneri. We extend our thanks to Earthplace Trustee and Trumbull resident, Mary Ellen Lemay for
guidance and help with Trumbull Town municipal departments.
References
CT DEEP, Water Quality Standards 2/25/11
CT DEEP, Pequonnock River Watershed TMDL, September 2012
Rice, E. W, A. D. Eaton, R. B. Baird, and L. S. Clesceri. Standard Methods, 22nd ed, 2012, Section
9222D and 9222G
Harris, R.B. and P.J. Fraboni: Quality Assurance/Quality Control Plan for the Pequonnock River
Watershed Monitoring Project (QAPP No. RFA#13058) (approved May 2013 and extended to
2016)
Fuss and O’Neill, Pequonnock River Watershed Based Plan, September 2011
Appendix A
Photos of selective monitoring sites in the Trumbull Section of the Pequonnock River
(left) Boom deployed down stream of
site PQ7 and the Spring Hill
Bridge collecting flock
(below) Water exiting at Site PQ7.01,
which has travelled
underground through a
rusting corrugated metal pipe,
showing signs of iron slime
bacteria
(above) Site PQ6.1 is an un-named
brook whose outfall enters
the lower end of the
Pequonnock River Valley
State Park. The water from
this stream flows through the
Norwood Terrace
neighborhood is
characterized with elevated
E. coli bacteria and
conductivity levels.
(left) Looking upstream from site
PQ6.2 in the Pequonnock River
Valley State Park