Water Quality Data Report For Sasco Brook Watershed May 2014 through September 2014

Transcription

1 Water Quality Data Report For Sasco Brook Watershed May 2014 through September 2014 Contaminated water discharging into Sasco Brook during the sanitary sewer leak in front of Stop and Shop on RT 1 in Westport on 8/28/2014 Richard Harris, Principal Investigator, Staff Scientist/Director of the Harbor Watch Program at Earthplace, Westport, CT, Phone (203) Peter Fraboni, Associate Director & QA/QC Officer for the Harbor Watch program at Earthplace, Westport, CT Nicole Cantatore, Lab Director for the Harbor Watch program at Earthplace, Westport, CT Joshua Cooper, Coastal Studies Technician for the Harbor Watch program at Earthplace, Westport, CT This project was funded in part by matching funds from the Connecticut Department of Agriculture through the Community Investment Act,

2 Table of Contents Introduction 3 Materials and Methods 7 Sub-watershed D Results 7 Sub-watershed D Discussion 12 Hunt Club Results 14 Hunt Club Discussion 17 Appendix A List of Figures and Tables i 2

3 Introduction Beginning in 1994, Harbor Watch, a program of Earthplace, The Nature Discovery and Environmental Learning Center in Westport, CT began monitoring Sasco Brook, the first of many assigned rivers and brooks under the guidance and sponsorship of the CT Department of Environmental Protection s Water Management Bureau 1. During the monitoring period of 1998, the fecal coliform group was the indicator bacteria of choice used by the CT DEEP to judge water quality for recreational use. Beginning in 2001 Escherichia coli (E. coli) the thermo-tolerant bacterium of the fecal coliform group became the indicator of choice for the CT DEEP classification of waters, because this bacterium is more indicative of recent enteric inputs to waterways. Characterized by moderate to heavy water quality impairment, Sasco Brook was among the first of Connecticut waterways to gain a Total Maximum Daily Load (TMDL) status in December of The TMDL set specific goal for each of the three aquatic Sub-watersheds A, B and C comprising Sasco Brook (Figure 1). The estuary, Sub-watershed D, was not included in the original TMDL analysis (Figure 1). The four sub-watersheds of Sasco Brook are characterized as follows: Sub-watershed A is located in the northern region of Sasco Brook watershed in Easton, Fairfield and Westport. It is characterized by large amounts of open land occupying 20 acres or more and residential neighborhoods with more modest homes. Some of the properties boarded one or more horses and other assorted farm animals. The area homes depend solely on septic systems. Thirteen sites were monitored in this Sub-watershed over three tributaries which converge at monitoring Site 1A. Sub-watershed B, also located in the northern region of the Sasco Brook watershed, is split between Fairfield and Westport. The land use is characterized as residential, with large homes on two or more acres of land, and small farms. Sixty acres of the 1922 acres are made up of wetlands and considered not suitable for structures. No large open land areas other than wetlands have been left open to the public. Six sites were monitored in this Sub-watershed. Sub-watershed C is located in the southern region of the Sasco Brook watershed in Westport and Fairfield. The southern-most boundary of the Sub-watershed is the dam at Bulkley Pond which serves as a barrier for tidal incursion. The land use is characterized by a mixture of farmland and residential use with older houses on one and two acres. Sub-watershed C is split between homes using septic and sanitary sewer systems. Site HC1 is located just before the confluence of the Fairfield Count Hunt Club property tributary to Sasco Brook. The rest of the sites are located near small residential properties. Six sites were monitored in this Sub-watershed relating to the Fairfield County Hunt Club (Figure 4). Sub-watershed D, the subject of this report, is the southernmost region of the Sasco Brook watershed which occasionally experiences tidal incursion. It is located just below the highly commercial Route 1 corridor, with many shopping plazas impacting the brook. Several monitoring sites located in Subwatershed D are storm drain discharge pipes which empty directly to Sasco Brook (Figure 2a, Figure 2b, Figure 3). The summer 2014 monitoring focused on this subwatershed due to past surveys which indicated that this area had the greatest number of hot spot areas. Funding for this monitoring project was supported by the Long Island Sound Futures Fund and the CT DEEP Department of Agriculture. 1 The CT DEP has been merged with the Department of Energy and is now the Department of Energy and Environmental Protection (CT DEEP) and the bureau is renamed the Bureau of Water Protection and Land Reuse. 3

4 Figure 1 Map of the sampling sites in the Sasco Brook Watershed 4

5 Figure 2a Lower level of the 7D storm drain system (Brown line indicates sewage leak travel path), the only portion of the leak above ground was from the brown dot to catch basin D7.12) Figure 2b Upper level of the 7D storm drain system 5

6 Figure 2c Map of the Stop and Shop parking lot area showing the sanitary waste line and route of the sanitary breakout leading into the Sasco Brook in Sub-watershed D 6

7 Figure 3 Storm drain system that discharges at 10.5D Figure 4 Map of Hunt Club sites 7

8 Materials and Methods Water monitoring is carried out under Quality Assurance Project Plan (QAPP) RFA#14102 approved by CT DEEP and EPA on 8/4/14 for five years. Monitoring teams depart from Earthplace in Westport at 9:30AM and return at 11:00 AM. The team is comprised of a fully trained Harbor Watch staff member and three volunteers. Water samples are collected at ten monitoring sites along the length of the river (Figure 1). These sites, which represent the more impacted sites and developed areas, were selected in concert with the CT DEEP, because results from the year one study consistently demonstrated elevated fecal coliform bacteria counts at these locations. 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 Harbor Watch data sheet. Upon return to the Earthplace 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 Harbor Watch bacteria log. During the summer monitoring period (June through September), sites were monitored weekly. 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 of recreational use (Table 1). The Sasco Brook is classified for all other recreational uses because people do not bathe in or drink the river water and it is too shallow for swimming. The report will focus on E. coli bacteria levels, because it is currently the preferred indicator bacteria used by the CT DEEP for water quality classification. Table 1 CT DEEP criterion for E. coli bacteria levels as applied to recreational use, effective 2/25/11 Designated Use Recreation Designated Swimming Non-designated Swimming All Other Recreational Uses Class Indicator Criteria AA, A, B AA, A, B AA, A, B Escherichia coli Escherichia coli Escherichia coli Geometric Mean less than 126 CFU/100mLs; Single Sample Maximum 235 CFU/100mLs Geometric Mean less than 126 CFU/100mLs; Single Sample Maximum 410 CFU/100mLs Geometric Mean less than 126 CFU/100mLs; Single Sample Maximum 576 CFU/100mLs CFU stands for Colony Forming Units. A colony is raised from a single bacterium to a visible colony for counting by providing the preferred heat range and media for 24 hours. 8

9 Sub-Watershed D Results Observed E. coli geomeans exceed the CT DEEP criteria of <126CFU/100mLs at 8 of the 10 sites (Figure 5, Table 2). Only three sites, 2D, 11D, and 10.6 D, passed the secondary CT DEEP criteria of the single sample maximum which requires that <10% of the samples exceed 576CFU/100mL (Table 2). With the exception of site 10.5, the observed means exceed the CT DEEP 5mg/L minimum for dissolved oxygen. Sites 6D, 7D, 9D, 10D, and 10.5D saw individual sampling days with observed dissolved oxygen levels below 5mg/L (Figure 6, Table 3). Observed conductivity values ranged from a minimum of 173µS at site 7D to 40343µS at site 11D. Conductivity means ranged from 231µS at site 1D to 29243µS at site 11D. Site 2D had the narrowest range at 76µS and site 10.5D had the widest range at 33528µS (Figure 7a, 7b). Rainfall during the monitoring saw a monthly average of 3.32in. The most rain fell in July with 3.79in total and the least rain fell in August with 2.4 in total (Figure 8). Figure 5 Maximum, geomean, and minimum E. coli values for ten sites in the Sasco Brook Subwatershed D from June through September Max Geomean Min E. coli Bacteria (CFU/100mLs) a 1 1D 2D 5D 6D 7D 9D 10D 10.5D 11D 10.6D Sites a CT DEEP geomean maximum for a Class B river 9

10 Table 2 Observed E. coli counts on each sampling date, geomeans, and % frequency exceeding 576 CFUs/100mLs for each site in the Sasco Brook Sub-watershed D from June through September /1/2014 6/11/2014 6/16/2014 6/23/2014 6/30/2014 7/7/2014 7/14/2014 7/21/2014 7/28/2014 1D D D D D 92 n/a D D 142 no access 640 no access no access no access 10.5D D D Rain (in) Days Prior % Frequency over 576 8/4/2014 8/11/2014 8/18/2014 8/25/2014 8/28/2014 9/2/2014 Geomean CFU/100mLs 1D % 2D % 5D TNTC % 6D no sample no sample % 7D no sample TNTC % 9D % 10D no access no sample no sample no sample no sample no sample % 10.5D no sample no sample % 11D % 10.6D no sample no sample 200 0% Rain (in) N/A Days Prior N/A 8/28/14: Harbor Watch notified of sewage spill due to broken sanitary line. 9/2/14: Testing conducted to determine impact of sewage infiltration on brook a few days after the spill. Green numbers indicate possible discrepancies in sample location. Three different team leaders monitored the brook and some samples were taken directly from the storm drain pipe while others were taken from the stream which is fed by 7D. The higher E. coli counts lead Harbor Watch to believe that the sample is from the stream and not the pipe (the pipe is the actual sample location). 10

11 Figure 6 Maximum, mean, and minimum dissolved oxygen values for nine sites in the Sasco Brook Subwatershed D from June through September Max Avg Min Dissolved Oxygen (mg/l) a 0.0 1D 2D 5D 6D 7D 9D 10D 10.5D 11D Sites a CT DEEP minimum criterion for dissolved oxygen for Class B river Table 3 Dissolved oxygen sampling dates that fell below 5mg/L at monitoring sites in subwatershed D Site Date DO mg/l 7/28/ D 7D 9D 8/4/ /11/ /18/ /25/ /23/ /28/ /14/ /28/ D 6/16/ /9/ /14/ /21/ D 7/28/ /4/ /11/ /18/ /25/

12 Figure 7a Maximum, mean, and minimum conductivity values for nine sites in the Sasco Brook Subwatershed D from June through September Max Avg Min Conductivity (µs) D 2D 5D 6D 7D Sites Figure 7b Maximum, mean, and minimum conductivity values for nine sites in the Sasco Brook Subwatershed D from June through September 2014 Conductivity (µs) Max Avg Min 9D 10D 10.5D 11D Sites 12

13 Figure 8 Rainfall over the monitoring period of June through September Rainfall (inches) June July August September Average Month Sub-watershed D Discussion Seven sites, 1D, 5D, 6D, 7D, 9D, 10D, and 10.5D exceeded both CT DEEP E. coli criteria for the 126CFU/100mL geomean maximum and the single sample maximum of <10% over 576CFU/100mLs. Site 10.6D exceeded only the geomean maximum with a value of 200mLs (Figure 5, Table 2). It is surprising to see site 2D pass both criteria. 2D is a storm drain discharge pipe that runs parallel with Route 1 through Westport. The pipe has visual signs of corrosion as well as discoloration on the rocks and river bed below the pipe from iron slime bacteria. At times chemical odors can be detected emitting from the pipe. Contamination from human sources is suspected within this line but Harbor Watch has been unable to pinpoint the source. One thought as to why the E. coli bacteria values are so low is due to chemicals within the pipe creating an environment which inhibits bacterial growth. Continued monitoring efforts to identify the chemical odor will occur in the future. Site 11D, which also passed both criteria, is located at the mouth of Sasco Brook and is heavily influenced by the tide (Figure 1, Figure 7b, and Table 2). Many days sampling was conducted during high tide which allowed dilution of the water flowing out to Long Island Sound resulting in lower bacteria counts than what is observed farther upstream. Site 7D has the second highest observed geomean for E. coli bacteria. For the past couple monitoring seasons this site has proven to be a random polluter to Sasco Brook even during the colder winter months (Figure 5, Table 2). From site 7D the storm drain was sampled back man-hole by man-hole on three different occasions during June and July 2014 (Table 4). Results proved to be inconclusive as to the source of the pollution partially due to low flow resulting from minimal rainfall. 13

14 Table 4 Storm drain system discharging at site 7D E. coli bacteria results 6/25/2014 7/1/2014 7/15/2014 Geomean 7D D D D 400 N/A D no sample D 1100 N/A no sample D no sample 207 Rain (in) Days Prior On August 28 th Harbor Watch was alerted to a sewage leak from a sanitary forced main that began in the parking lot of Stop and Shop on Route 1 in Westport, flowed across the shopping plaza, entered catch basin site D71.2 and discharged behind Home Goods(Figures 2a, 2b, 2c, and 4a) at site 7D (cover photo). From there the sewage flowed down a short creek to impact Sasco Brook just above site 5D. By the time Harbor Watch arrived on the scene to begin bacteria sampling, Westport Public Works Department had already begun the process of remediating the leak, beginning with exposing the broken pipe and emptying the line so repairs could be made. Harbor Watch was informed that a hydrogen sulfide gas build up in the sanitary sewer had caused corrosion through the crown of the aging pipeline. Over time the pipe failed which allowed pressurized sewage to overflow up through the asphalt on to the Stop and Shop parking lot. Monitoring of this area will continue in order to determine if prior to the pressurized sewage breaking through the asphalt it had already been infiltrating the storm drain system and was possibly a major source for bacterial pollution at site 7D (Figures 2a and 2c). Subsequent testing of key impact sites by Harbor Watch on 9/2/14 shows sewage pollution subsiding (Table 2). Approximately 10 years ago another sanitary line running across the adjoining Home Goods parking lot was clogged with grease from a nearby Chinese restaurant, the Tiger Bowl (Figure 2c). This event caused sewage to back up into the parking lot and infiltrate Sasco Book. The pipeline was cleared immediately but the Conservation Department in Fairfield still believed sewage pollution was continuing to discharge to the brook. To that end, a dye test was performed during the first week in August 2014 down toilets and sinks at Home Goods by Harbor Watch and Westport s Public Works to determine the integrity of the adjoining storm drain system. The dye did not appear in Sasco Brook but was visible in the sewer line just before it entered the pump station. All parties are finally satisfied that a hypothetical pollution issue with the Home goods parking lot does not exist. Site 10.5D had the highest observed E. coli bacteria geometric (Figure 5, Table 2). This site is also a discharge point for a storm drain system that is located in Fairfield, CT. Tom Steinke, Director of Conservation in Fairfield, CT, gave Harbor Watch a map of the storm drain system which assisted in preliminary testing of the pipeline. The results of this testing can be seen in Table 5. 14

15 Table 5 Storm drain system discharging at site 10.5D E. coli bacteria results 8/26/ D D D D D 10 Rain (in) 0.28 Days Prior 4 This sampling indicates that further investigation along the 10.53D branch of the storm drain system should be tested in detail. Monitoring will continue through the fall of Due to the relatively dry summer, flow in Sasco Brook dropped below normal, especially towards the end of July and August, and dissolved oxygen levels were observed to fall below the CT DEEP criteria of 5mg/L (Figure 6, Table 3). Site 6D is a storm drain discharge pipe, but since water level in the pipe is not always deep enough to get a reading with the probes readings are taken from the stream bed directly below the pipe which is fed in part by site 7D. This makes it is understandable that both 6D and 7D experienced low dissolved oxygen levels. Sites 9D and 10D experienced their low dissolved oxygen levels on sampling days that occurred during periods of low to no rainfall with the exception of 9D on 7/14/14 (Table 2, Table 3). This low value is possibly the result of the DO probe having accidently been partially submerged in the muddy brook bottom. Site 10.5D never had observed dissolved oxygen readings above 2.0mg/L and this can be attributed to the water being very stagnant in combination with a large amount of decomposing organic matter (Table 3). Observed conductivity values have a wide range across all ten sites due to the fact that many sites lie within the estuary of Sasco Brook and are tidally influenced upstream as far as site 5D during the full moon. Hunt Club Results Observed E. coli geometrics exceed the CT DEEP criteria of <126CFU/100mLs at all seven sites (Figure 9, Table 6). All sites also exceeded the secondary CT DEEP criteria, the single sample maximum, which only allows <10% of the samples to exceed 576CFU/100mL (Table 6). With the exception of site HC0.5, the observed DO means exceed the CT DEEP 5mg/L minimum for dissolved oxygen. Sites HC0.3 and HC0.5 experienced individual sampling days with observed dissolved oxygen levels below 5mg/L (Figure 10, Table 7). Observed conductivity values ranged from a minimum of 132µS at site HC0.1 to 5143µS also at site HC0.1. Conductivity means ranged from 210µS at site SB5.5 to 325µS at site HC0.1. Site SB5.6 had the narrowest range at 66µS and site HC0.1 had the widest range at 382µS (Figure 11). 15

16 Figure 9 Maximum, geometric mean, and minimum E. coli values for seven sites in the Hunt Club from May through August E. coli Bacteria (CFU/100mLs) Max Geomean Min HC0.1 HC0.3 HC0.5 HC1 HC2 SB5.5 SB5.6 Sites a CT DEEP geometric maximum for a Class B river a Table 6 Observed E. coli counts on each sampling date, geometric means and % frequency exceeding 576 CFUs/100mLs for seven sites in the Hunt Club from May through August 2014 a a a a b b b b % Frequency over 576 5/21/2014 6/5/2014 6/17/2014 6/18/2014 6/20/2014 6/23/2014 7/9/2014 7/23/2014 8/12/2014 8/13/2014 8/14/2014 8/15/2014 Geomean CFU/100mLs HC0.1* 132 fecal tntc fecal tntc 1400 no flow no flow no flow no flow no flow % HC0.3 no sample % HC fecal tntc % HC1* 192 fecal tntc fecal tntc % HC2 272 fecal tntc no transfer % SB fecal tntc 180 no sample % SB no sample % Rain (in) Days Prior *Geomean is lower than acutal because two days during the show the bacteria was too numerous to count. Effects from HC0.1 can be seen at HC1 and HC2. a Dates of June horse show, 300 extra horses on property b Dates of August horse show, 300 extra horses on property 16

17 Figure 10 Maximum, mean, and minimum dissolved oxygen values for seven sites in the Hunt Club from May through August Dissolved Oxygen (mg/l) a Max Avg HC0.1 HC0.3 HC0.5 HC1 HC2 SB5.5 SB5.6 Sites a CT DEEP minimum criterion for dissolved oxygen for Class B river Table 7 Dissolved oxygen values below 5mg/L in the Hunt Club monitoring area Site Date DO mg/l HC0.3 7/9/ /17/ /18/ HC0.5 6/20/ /23/ /9/ /23/

18 Figure 11 Maximum, mean, and minimum conductivity values for seven sites at the Hunt Club from May through August Max Avg Min 500 Conductivity (µs) HC0.1 HC0.3 HC0.5 HC1 HC2 SB5.5 SB5.6 Sites Hunt Club Discussion Monitoring of the seven sites in and around the Fairfield County Hunt Club are conducted yearly focusing heavily on collecting samples during the June and August Horse Shows. These shows attract many participants increasing the number of horses boarded on the property from approximately 85 to over 300. The large number of horses in conjunction with unfortunate rainfall events, create a heavy impact to the health of the brook. Relatively low E. coli counts are observed on 5/21, 6/17, and 7/9 which were collected prior to the horse shows beginning (Table 6). The property is only 30 acres which makes environmental management a very difficult task. The majority of values reflected in this report represent the extreme annual impact for this property. While all seven sites monitored around the time of the two Horse Shows exceed both criteria set by the CT DEEP, it is important to note that over the last five Horse Shows in the month of June between 2010 and 2014, a general downward trend of E. coli bacteria has been observed (Figure 12). The downward trend can be attributed to the efforts made by the Fairfield County Hunt Club to create more environmentally conscious waste management, horse washing stations, and the installation of a swale to filter pollutants before they enter the brook. 18

19 Figure 12 Graph of the last five June Horse Shows and the E. coli bacteria geomeans observed at the four sites on the Fairfield County Hunt Club property Observed dissolved oxygen levels which fail to meet the CT DEEP minimum of 5mg/L at sites HC0.5 and HC0.3 were observed due to low flow and below average rainfall during the summer of 2014 (Figure 10, Table 7). Sites HC0.3 and HC0.5 sit within a wetland area that is fed by two very shallow streams. Site HC0.5 also has a very muddy bottom caused by the decaying organic matter within the wetlands which possibly uses much of the dissolved oxygen that may have been available. Meetings with the Fairfield County Hunt Club Manager, the architect of the new swale, the Conservation Director of Westport, and Harbor Watch Director will occur in the near future to discuss the current state of Sasco Brook in relation to the Hunt Club. Plans will be made to try and continue improving the water quality of the Hunt Club tributary (Figure 4) which ultimately has a bearing on the health of Sasco Brook. An issue is the apparent variable performance of the recently completed 300 foot swale which collects the storm drain runoff from the yard area surrounding the seven barns. The purpose of the swale is to reduce bacteria and nutrients by allowing the surface runoff and the storm drain input to slowly percolate through the swale s surface plantings and substantial earth barrier before being discharged to the small tributary (site HC0.1) at the far end. 19

20 Appendix A List of Figures and Tables Figure 1 Map of the sampling sites in the Sasco Brook Watershed 4 Figure 2a Lower level of the 7D storm drain system (Brown line indicates sewage leak travel path, only section above ground was from the brown dot to D7.12) 5 Figure 2b Upper level of the 7D storm drain system 5 Figure 2c Map of the Stop and Shop parking lot area showing the sanitary waste line and route of the sanitary breakout leading into the Sasco Brook in Sub-watershed D 6 Figure 3 Storm drain system that discharges at 10.5D 7 Figure 4 Map of Hunt Club sites 7 Figure 5 Maximum, geomean, and minimum E. coli values for ten sites in the Sasco Brook Sub-watershed D from June through September Figure 6 Maximum, mean, and minimum dissolved oxygen values for nine sites in the Sasco Brook Sub-watershed D from June through September Figure 7a Maximum, mean, and minimum conductivity values for nine sites in the Sasco Brook Sub-watershed D from June through September Figure 7b Maximum, mean, and minimum conductivity values for nine sites in the Sasco Brook Sub-watershed D from June through September Figure 8 Rainfall over the monitoring period of June through September 13 Figure 9 Maximum, geomean, and minimum E. coli values for seven sites in the Hunt Club from May through August Figure 10 Maximum, mean, and minimum dissolved oxygen values for seven sites in the Hunt Club from May through August 2014or six sites in the Sasco Brook Sub-watershed B 17 from May through August 2014 Figure 11 Maximum, mean, and minimum conductivity values for seven sites in the Hunt Club from May through August Figure 12 Graph of the last five June Horse Shows and the E. coli bacteria geomeans observed at the four sites on the Fairfield County Hunt Club property 19 Table 1 CT DEEP criterion for E. coli bacteria levels as applied to recreational use, effective 2/25/11 8 Table 2 Observed E. coli counts on each sampling date, geomeans, and % frequency exceeding 576 CFUs/100mLs for each site in the Sasco Brook Sub-watershed D from 10 June through September 2014 Table 3 Dissolved oxygen sampling dates that fell below 5mg/L at monitoring sites in subwatershed D 11 Table 4 Storm drain system discharging at site 7D E. coli bacteria results 14 Table 5 Storm drain system discharging at site 10.5D E. coli bacteria results 15 Table 6 Observed E. coli counts on each sampling date, geomeans, and % frequency exceeding 576 CFUs/100mLs for seven sites in the Hunt Club from May through 16 August 2014 Table 7 Dissolved oxygen sampling dates that fell below 5mg/L in the Hunt Club monitoring area 17 i