Tankerhoosen River Watershed Water Quality Monitoring Study. Friends of the Hockanum River Linear Park of Vernon, Inc. Vernon, Connecticut.

Transcription

1 Tankerhoosen River Watershed Water Quality Monitoring Study Friends of the Hockanum River Linear Park of Vernon, Inc. Vernon, Connecticut March 2007 Fuss & O Neill, Inc. 78 Interstate Drive West Springfield, MA 01089

2 SECTION TANKERHOOSEN RIVER WATERSHED WATER QUALITY MONITORING STUDY Friends of the Hockanum River Linear Park of Vernon, Inc. TABLE OF CONTENTS PAGE 1.0 INTRODUCTION AND STUDY DESCRIPTION Tankerhoosen River Watershed Study Objectives Study Methods Chemical Water Quality Monitoring Biological Assessments Monitoring Locations Quality Assurance Project Plan RESULTS Description of Monitoring Events Water Quality Results Biological Monitoring Results Connecticut River Watch Program RBV Monitoring Tankerhoosen River State of the Watershed Assessment Fuss & O Neill Rapid Bioassessment CONCLUSIONS AND RECOMMENDATIONS Conclusions Recommendations REFERENCES...32 TABLES PAGE 1-1 Tankerhoosen River Watershed Monitoring Locations RBV Benthic Macroinvertebrate Sampling Results October 2006 Bioassessment Results Biometric Summary...28 FIGURES PAGE 2-1 Monthly Precipitation Totals, Windsor Locks, Connecticut Water ph Tankerhoosen River Watershed Dissolved Oxygen - Tankerhoosen River Watershed Specific Conductivity - Tankerhoosen River Watershed Turbidity Tankerhoosen River Watershed Total Suspended Solids Tankerhoosen River Watershed Total Coliform - Tankerhoosen River Watershed E. coli - Tankerhoosen River Watershed Dissolved Copper Tankerhoosen River Watershed Lead Tankerhoosen River Watershed Nitrogen Species Tankerhoosen River Watershed Ammonia - Tankerhoosen River Watershed Phosphorus Tankerhoosen River Watershed...21 F:\P2005\0257\A10\TWS report doc i

3 TANKERHOOSEN RIVER WATERSHED WATER QUALITY MONITORING STUDY Friends of the Hockanum River Linear Park of Vernon, Inc. TABLE OF CONTENTS (continued) APPENDICES A Water Quality Monitoring Results B Field Data C Phoenix Environmental Laboratories Laboratory Reports D Aquatec Biological Sciences, Inc. Laboratory Report END OF REPORT F:\P2005\0257\A10\TWS report doc i

4 1.0 INTRODUCTION AND STUDY DESCRIPTION 1.1 Tankerhoosen River Watershed The Tankerhoosen River is considered among one of the most important rivers within the Hockanum and Connecticut River watersheds. Its historic levels of high water quality and aquatic life have been hallmarks of a healthy ecosystem. Large areas of open space along the headwaters have helped to sustain these conditions. Water quality from the headwaters to Tankerhoosen Lakes has been classified by the Connecticut Department of Environmental Protection (CTDEP) as A, which is potentially suitable as a drinking water supply. From the Lakes to the confluence with the Hockanum River, the water quality is classified as B, which is suitable for fishing and contact recreation, with a goal of A. The Tankerhoosen River watershed is 12.9 square-miles, with approximately 90 percent of the watershed within the boundaries of the Town of Vernon. Other towns with land area within the Tankerhoosen River watershed are Tolland, Bolton, and Manchester. The Tankerhoosen River originates at the Walker Reservoir in Tolland, and flows west for approximately five miles to the Hockanum River in Vernon. The river itself is a moderate sized (16 ft. wide) upland stream. The headwaters region of the river is bisected by Interstate 84. Recent development pressure in this region poses a major threat to the long-term health of the watershed. In particular, development along Gages Brook, a key headwaters stream in the Tolland Industrial Park, and at the Exit 67 interchange of Interstate 84 are creating further stress on the headwaters region. Large areas of protected space, most notably the 282-acre Belding Wildlife Management Area (WMA), are a unique feature of the upper reaches of the river. The portion of the Tankerhoosen River that flows through the Belding WMA features a robust population of wild native brook trout and wild brown trout and is one of only two such Class 1 Wild Trout Management Areas (WTMA) east of the Connecticut River. Impairments have been identified in the lower reaches of the Tankerhoosen River. A portion of the lower Tankerhoosen River was cited as impaired in the CTDEP s most recent List of Connecticut Waterbodies Not Meeting Water Quality Standards. The causes and sources of impairment in the lower reaches of the Tankerhoosen River are currently listed as unknown, although nonpoint source impacts from stormwater runoff are likely contributors to the water quality problems in the lower reaches of the Tankerhoosen River. 1.2 Study Objectives This study, which was funded through a Long Island Sound Futures Fund Grant from the National Fish and Wildlife Foundation and by the Town of Vernon, consisted of the development and implementation of the first year of an annual monitoring program within the Tankerhoosen River watershed, including the collection and evaluation of chemical and biological water quality monitoring data at key locations within the watershed. The objective of the monitoring program is to establish current baseline water quality conditions in the watershed, identify water quality impacts from potential point and non-point pollution sources, begin developing a water quality database for the watershed to guide environmental decision-making and measure the progress toward meeting water quality goals in the watershed. The monitoring program developed as part of this study also complements other ongoing assessment efforts in the watershed, which are being undertaken in support of the development of a state of the watershed report and comprehensive watershed management plan for the Tankerhoosen River watershed. These additional studies F:\P2005\0257\A10\TWS report doc 1

5 include a wildlife inventory and biodiversity assessment, and streamwalk surveys and benthic macroinvertebrate studies by citizen volunteers. 1.3 Study Methods The annual monitoring program consists of two components chemical water quality monitoring and biological assessments at various locations along the Tankerhoosen River and selected tributaries Chemical Water Quality Monitoring The chemical water quality monitoring program consisted of two rounds of wet weather sampling and two rounds of dry weather sampling at selected monitoring locations to assess wet and dry weather impacts. Dry weather samples were collected after at least 72 hours of dry weather (no previous storms of 0.1 inch or greater). Wet weather samples were collected during or immediately following storms with more than 0.5 inches of rainfall and that occurred at least 72 hours after a previous storm event of 0.1 inch or greater (i.e., following a minimum 72-hour antecedent dry period). Samples were collected during late-summer (August) and mid-fall (October and November), periods of the year with a high potential for water quality impacts. It was anticipated that late-summer would better quantify impacts during low-flow conditions when there is little dilution available, while sampling was performed in the fall to coincide with the biological assessment and to quantify impacts of heavy rainfall. Sampling was attempted in the spring, although a suitable spring storm event that met the wet weather criteria did not occur during the study. Grab samples were collected at the mid-point and mid-depth of the stream/river channel at each location. Samples were collected using a dedicated sample scoop and waders. Other information that was recorded for each sample collected included the date, time, day of week, and weather conditions (temperature, precipitation, and previous rainfall). Samples were analyzed by Phoenix Environmental Laboratories in Manchester, Connecticut. The following chemical parameters were monitored at each location: Temperature, ph, and Dissolved Oxygen Temperature, ph, and dissolved oxygen are general indicators of water quality. Water temperature generally reflects seasonal fluctuations in ambient temperatures. Extreme temperature fluctuations in the river may be indicative of thermal pollution due to stormwater runoff from impervious surfaces or high-temperature wastewater discharges. Temperature can affect the ability of water to hold oxygen as well as the ability of organisms to resist certain pollutants. ph is the measure of the acidity or alkalinity of a solution. 6.5 to 8.0 are considered an acceptable range of ph for most surface waters (Connecticut Water Quality Standards). Extreme fluctuations from this range are detrimental to water quality and aquatic organisms. Low ph levels accelerate the release of heavy metals from sediments on the stream bottom. Dissolved oxygen is an important indicator of habitat quality and ecosystem condition. Dissolved oxygen is necessary in aquatic systems for the survival and growth of aquatic organisms. The Connecticut Water Quality Standards establish a criterion for dissolved oxygen of 5 mg/l. F:\P2005\0257\A10\TWS report doc 2

6 Prolonged exposure to dissolved oxygen below this level may increase organisms susceptibility to environmental stresses (CCRPA, 2004). Conductivity The ability of water to conduct electricity is highly dependent on the amount of ions present. In natural waters, this is mostly dissolved, dissociated inorganic solids in the water. Therefore, conductivity is a measure of the concentration of dissolved salts. Specific conductivity is commonly expressed in units of millisiemens per centimeter (ms/cm). Specific conductivity values of 0.05 to 0.1 ms/cm are common in surface waters with relatively pristine watersheds. Specific conductivity values of 0.5 to 1.5 ms/cm are common in surface waters of developed watersheds. Alkalinity and Hardness Alkalinity refers to the buffering capacity of the water. Low alkalinity indicates that the water has less ability to resist changes in ph from natural and anthropogenic sources. Typical alkalinity values for surface waters range from 20 to 200 mg/l (as calcium carbonate). Hardness represents the amount of dissolved calcium and magnesium in water, which enters a stream or river mainly through weathering of rocks. Turbidity and Total Suspended Solids Turbidity is a measure of the amount of light intercepted by the water column due to the presence of suspended and dissolved matter. Turbidity is measured in Nephelometric Turbidity Units (NTU). The Connecticut Water Quality Standards establish a turbidity criterion of 5 NTU over ambient levels. Suspended particulates such as clay, silt, sand, suspended algae, and particles in runoff reduce the clarity of water bodies in the Tankerhoosen River Watershed. Although pristine streams experience an increase of suspended solids during erosive high flow events, development within the watershed can cause persistent higher turbidity. Increased turbidity reduces the amount of light available for aquatic vegetation. Less photosynthesis and decaying plants depletes oxygen levels in the water, and thus degrades fish habitat. Additionally, fine particulate sediment abrades sensitive fish and insect gills. Silt accumulating on the stream bed can suffocate newly hatched larvae and fill spaces inhabited by benthic aquatic organisms. Total Coliform and E. coli Coliforms are a group of bacterial organism historically used as an indicator of sanitary quality in surface waters. Escherichia coli (E. coli) is a fecal coliform, a type of bacteria associated with human and animal waste. The presence of E. coli in water is a strong indication of recent sewage or animal waste contamination. Sewage may contain many types of disease-causing organisms. During rainfall, snowmelt, or other types of precipitation, E. coli may be washed into creeks, rivers, streams, lakes, or groundwater. For recreational waters, the USEPA recommends the use of E. coli because it is a better indicator of a human health risk from water contact than the fecal coliform parameter. The CTDEP criteria for total coliforms and E. coli bacteria levels as applied to recreational use for Class A and Class B waters are single sample maximums of 500 colonies/100 ml and 235 colonies/100 ml (designated swimming areas), respectively. F:\P2005\0257\A10\TWS report doc 3

7 Nitrogen Excessive nitrogen loadings have led to hypoxia, a condition of low dissolved oxygen, in Long Island Sound. Nitrogen fuels the growth of algae in the Sound, which eventually decays, consuming oxygen in the process (DEP, 2001). A Total Maximum Daily Load (TMDL) for nitrogen has been developed for Long Island Sound, which will restrict nitrogen loadings from point and nonpoint sources throughout Connecticut. The EPA recommended Total Nitrogen criterion for rivers in Ecoregion XIV is 0.71 mg/l (EPA, 2000). Total Nitrogen is comprised of Total Kjeldahl Nitrogen (TKN), nitrite, and nitrate. Total Kjeldahl Nitrogen consists of ammonia and organic nitrogen. High measurements of TKN are an indicator of sewage and manure discharges to water bodies. Ammonia is a common byproduct of animal waste that easily converts to nitrate in streams and rivers. The USEPA and CTDEP acute and chronic ammonia criteria are dependent on ph, temperature, and fish species. Nitrate can reach high levels that can potentially cause the death of fish. In most cases of excess nitrate concentrations, the principal pathway of entering aquatic systems is through surface runoff from agricultural or landscaped areas which have received excess nitrate fertilizer. High levels of nitrate can also lead to eutrophication and induce algal blooms in marine environments. Phosphorus Phosphorus is typically the growth-limiting nutrient in freshwater systems and is responsible for the growth of algae and eutrophication of fresh waterbodies such as lakes, ponds, and low gradient streams. According to the Connecticut Water Quality Standards (DEP, 2002), spring and summer phosphorus concentrations for lakes that would be expected to result in full support for contact recreational uses are less than 0.03 mg/l. This is consistent with the EPA recommended Total Phosphorus criterion for rivers in Ecoregion XIV (EPA, 2000). Heavy Metals The presence of heavy metals such as such as copper, lead, zinc, mercury, and cadmium in surface waters can be toxic to aquatic organisms, can bioaccumulate, and have the potential to contaminate drinking water supplies. Although metals generally attach themselves to the solids in stormwater runoff or receiving waters, recent studies have demonstrated that dissolved metals, particularly copper and zinc, are the primary toxicants in stormwater runoff from industrial facilities throughout Connecticut (DEP, 2004b). Many major rivers in Connecticut have copper levels that exceed Connecticut s Copper Water Quality Criteria. Copper toxicity is enhanced by depression of ph and hardness/alkalinity, and elevation of temperature. Copper may interact synergistically with ammonia to enhance toxicity. In aquatic organisms, lead exposure can impact respiration by causing excess mucus formation that coats the gills. In vertebrates, neurological impairment, kidney dysfunction, and anemia are all symptoms of lead poisoning. Low alkalinity water may be an important co-factor in toxicity. Zinc is naturally found in air, soil, and water. However, macroinvertebrates such as mollusks, crustaceans, and odonates are particularly sensitive to elevated concentrations in water. Toxicity is enhanced by depression of ph and hardness/alkalinity, and elevation of temperature. F:\P2005\0257\A10\TWS report doc 4

8 Chloride Where it does not naturally occur, the presence of chloride can indicate possible water pollution by materials such as road salt. Chloride is often used as a general indicator of non-point source pollution. Chloride itself is not harmful to macroinvertebrates until it reaches very high concentrations (1,000 mg/l) Biological Assessments Benthic macroinvertebrates are bottom dwelling aquatic organisms that can be seen with the unaided eye. Examples of such organisms include stonefly, mayfly, and caddisfly nymphs. Benthic macroinvertebrates are used as indicators of water quality for several reasons: Many are sensitive to pollution, The composition of the community is a good reflection of long-term water quality, They cannot easily escape pollution, and They are easy to collect. A biological assessment was performed as part of this study in the fall of 2006 in conjunction with one round of dry weather chemical water quality monitoring. The biological assessment consisted of field surveys of the benthic macroinvertebrates and physical habitat of selected locations along the Tankerhoosen River and its tributaries following the EPA Rapid Bioassessment Protocol. The protocol included laboratory processing of macroinvertebrate samples under controlled conditions by Aquatec Biological Sciences, Inc. Several other sources of recent biological monitoring data are available for the Tankerhoosen River watershed, including biological assessments performed in 2004 by Jane Seymour, Wildlife Consultant, and annual biological monitoring by citizen volunteers under the Connecticut River Watch Program and the CTDEP, including biological assessments performed in the fall of 2005 and Biological monitoring results from the current study and these related efforts are summarized in this report. The Connecticut Department of Environmental Protection has developed a biological monitoring protocol called Rapid Bioassessment in Wadeable Streams and Rivers by Volunteer Monitors (RBV). This program trains volunteers to collect benthic macroinvertebrates from shallow riffle areas by disturbing the stream bottom and catching the dislodged organisms in a net. The RBV protocol is a screening tool designed to help identify streams with pollution-sensitive benthic macroinvertebrate communities, and to identify streams with either very high or very poor water quality. There are 26 organisms included in the RBV protocol and are easily identified by their distinct shape, structure, color, or behavior. Each benthic macroinvertebrate also provides key information about the stream environment. RBV organisms are categorized in one of three groups: Most Wanted Most sensitive to pollution, requiring a narrow range of environmental conditions. Abundant numbers are a sign of a non-impaired stream. Moderately Wanted Less sensitive to pollution and found in a variety of water quality conditions. Abundant numbers are not a strong indicator of upstream water quality. F:\P2005\0257\A10\TWS report doc 5

9 Least Wanted Least sensitive to pollution and tolerant of the widest range of conditions. Samples with this majority indicate some level of water quality impairment. The Connecticut River Watch Program, in cooperation with the Hockanum River watershed stakeholder groups and the CTDEP, performed RBVs in 2002, 2003, 2004, 2005, and 2006 in the Tankerhoosen River. It is important to note that extreme weather conditions in the summer and fall of 2005 are believed to have affected results of the 2005 RBV. Near-drought conditions in the summer resulting in very low-flows were followed by record rainfall in early to mid-october This combination of events made it difficult to determine whether riffle areas being sampled were wet throughout the summer. In addition, very high flows after the storm events scoured stream bottoms and moved substrate materials, washing away macroinvertebrates or burying their habitat. According to the CTDEP, RBV samples collected after October 8, 2005 are not representative of the macroinvertebrate community prior to the rain, and the absence of types of organisms from the samples cannot be associated with a decrease in water quality (CTDEP, 2006). Therefore, the 2005 RBV results are presented in this report for informational purposes, but should be considered of questionable value. 1.4 Monitoring Locations Chemical and biological monitoring locations were selected in conjunction with representatives of the Friends of the Hockanum River Linear Park of Vernon, Inc. and other project team members based on a number of factors including: The suitability for biological monitoring (i.e., pool and riffle areas), To obtain geographic coverage throughout the watershed, including both developed and undeveloped areas for evaluating non-point source impacts, To complement but avoid redundancy with the RBV locations monitored under the Connecticut River Watch Program, To evaluate likely point sources such as roadway crossings, storm drainage system outfalls, and areas of residential or commercial development along the watercourses. Access to sample locations, and Watershed land use, which is depicted in Figure 1-1. A total of 12 locations were selected for chemical water quality monitoring along the Tankerhoosen River, Gages Brook, an unnamed tributary to Gages Brook, Clarks Brook, and Railroad Brook. Biological assessments were performed at 7 of these locations. The monitoring locations and selection rationale are provided in Table 1-1, including the Connecticut River Watch Program RBV locations. The monitoring locations for this study and the Connecticut River Watch Program RBV are also depicted on the map in Figure Quality Assurance Project Plan The monitoring program for this study, including the chemical water quality monitoring and the biological assessments, was carried out under an EPA-approved Quality Assurance Project Plan (QAPP). The purpose of the QAPP is to ensure that sampling, sample analysis, and the resulting data are of sufficient quality to meet the study objectives. The QAPP defines the scope of work, policies, organization, data quality objectives (DQO), and functional activities associated with the project. The QAPP is consistent with the most recent version of the USEPA and the CTDEP quality assurance guidance documents. F:\P2005\0257\A10\TWS report doc 6

10 Figure 1-1: Tankerhoosen River Watershed Land Use F:\P2005\0257\A10\TWS report doc 7

11 Figure 1-2: Tankerhoosen River Watershed Monitoring Locations F:\P2005\0257\A10\TWS report doc 8

12 Site ID Previous RBV Site ID Table 1-1: Tankerhoosen River Watershed Monitoring Locations Water Body Location Rationale GB1 Gages Brook Old Post Road (upstream) Upstream of I-84 and industrial park, Gages Brook reference site Monitoring Type Biological 1 GB2 HR7d Gages Brook Behind Tolland Agricultural Center Gages Brook upstream of I-84 RBV F&O GB3 Gages Brook Tributary South shoulder I-84 Upstream of I-84 crossing, reference site F&O F&O GB4 Gages Brook Tributary North shoulder I-84 Downstream of I-84 crossing, highway impacts F&O F&O GB5 Gages Brook Inlet to Walker Reservoir East Downstream of I-84 interchange, highway impacts (not suitable for biomonitoring, primarily sandy bottom, absence of riffles) F&O Not suitable TR1 Tankerhoosen River Fish and Game Road (upstream) Upstream Tankerhoosen site F&O F&O TR2 HR7b Tankerhoosen River Bolton Road (downstream) Midstream Tankerhoosen site RBV F&O TR3 HR7a Tankerhoosen River Tunnel Road (upstream) TR4 HR7c Tankerhoosen River TR5 Tankerhoosen River Downstream of Dobsonville Pond 2 (Talcotville Gorge area) Downstream of Dobsonville Pond (Talcotville Gorge area) Mid-stream Tankerhoosen site (downstream of agriculture) RBV Chemical F&O F&O Upstream of I-84 stormwater basin RBV F&O Downstream of I-84 stormwater basin, highway impacts TR6 HR7 Tankerhoosen River Golfland, near confl. w/hockanum Lower Tankerhoosen site, watershed outlet RBV F&O CB1 Clarks Brook Bolton Road (downstream) Downstream of I-84 (highway impacts) F&O F&O F&O F&O RB1 Railroad Brook Valley Falls Road (upstream) 3 Downstream of undeveloped areas, reference site F&O F&O 1 Biomonitoring conducted at the previous RBV sites as part of continuing volunteer efforts under the CT River Watch Program. 2 Mike Beauchene of DEP recommended reinstating the Talcotville Gorge biomonitoring site, provided that it is at least ¼ mile downstream of the dam at Dobsonville Pond. 3 An alternate monitoring location is upstream of Valley Falls Pond if the scheduled pond dredging project is ongoing at the time of sampling. F&O = indicates monitoring performed by Fuss & O Neill, Inc. RBV = indicates monitoring performed by volunteers under the CT River Watch Program Biomonitoring performed by Fuss & O Neill followed the EPA Rapid Bioassessment Protocol (RBP). F:\P2005\0257\A10\TWS report doc 9

13 2.0 RESULTS 2.1 Description of Monitoring Events Dry Weather The first dry weather monitoring event occurred on November 2 and 3, During these two days, there was no recorded precipitation, and the temperature averaged between 57 and 66 degrees F (Weather Underground, Hartford monitoring station). Monitoring was performed for chemical water quality parameters only, as extreme weather conditions in the summer and fall of 2005 (near-drought conditions in the summer 2005 resulting in very low-flows followed by record rainfall in early to mid-october 2005) resulted in in-stream conditions that were unsuitable for collection of representative benthic macroinvertebrate samples. The November 2 and 3, 2005 water quality monitoring event was preceded by 7 days without measurable precipitation, although a record amount of precipitation was recorded for the month of October, The prior measurable rainfall event (1.76 inches) occurred on October 25, preceded by a significant rainfall of 1.76 inches on October 25. Prior to this, a storm occurred that produced a historical crest on the Hockanum River on October 15, During the period of October 12 through 14, Vernon, Connecticut recorded 5.45 inches of rainfall. Flows in the Hockanum River during early November 2005 were significantly greater than the historical average monthly flows in the Hockanum River for November (USGS, East Hartford, CT). The second dry weather monitoring event occurred on October 25 and 26, 2006, which included both chemical water quality monitoring and a biological assessment. There was no recorded precipitation during these two days or during five days preceding the monitoring event, and the temperature averaged between 50 and 53 degrees F. The prior measurable rainfall event occurred on October 20, 2006, when 0.37 inches of rain was recorded. Flows in the Hockanum River during late October 2006 were approximately 90% percent of the historical average monthly flow for October (USGS, East Hartford, CT). Wet Weather The first wet weather monitoring event occurred on August 15, The average temperature for this date was 76 degrees F, and 0.87 inches of precipitation was recorded, with a maximum rainfall intensity of 0.40 inches per hour. The previous measurable rainfall occurred on August 10, producing 0.25 inches of rain. The first half of August was generally dry, with only three rain events of 0.25 inches or greater. Flows in the Hockanum River just prior to the sampling event were approximately 85% percent of historical average daily flows in the Hockanum River for August (USGS, East Hartford, CT). During the sampling event, flows in the Hockanum River were significantly greater than the historical average. The second wet weather monitoring event occurred on October 12, A total of 0.37 inches of rain was recorded for this date, with a maximum rainfall intensity of 0.41 inches per hour, and the average temperature was 62 degrees F. The prior measurable rainfall occurred on October 1, when 2.21 inches of rain were recorded. During the sampling event, flows in the Hockanum River greatly exceeded the historical average. F:\P2005\0257\A10\TWS report doc 10

14 A summary of monthly precipitation totals for the sampling period is presented in Figure 2-1. Precipitation was generally light to average through the winter and early spring of 2006, followed by a period of above-average precipitation through the fall of Precipitation (inches) Oct-05 Nov-05 Actual Average Dec-05 Jan-06 Feb-06 Mar-06 Apr-06 May-06 Jun-06 Jul-06 Aug-06 Sep-06 Oct-06 Nov-06 Figure 2-1: Monthly Precipitation Totals, Windsor Locks, Connecticut 2.2 Water Quality Results The water quality monitoring data are provided in tabular format in Appendix A. Associated field documentation (data sheets, notes, etc.) and laboratory data reports are also provided in the report appendices. The monitoring results are discussed below for each of the chemical water quality parameters. ph, Temperature and Dissolved Oxygen Measured water temperatures reflect similar seasonal temperature variability at each of the watershed monitoring locations. On average, water temperatures were somewhat higher in the lower reaches of the Tankerhoosen River, likely due to thermal enrichment associated with stormwater runoff from more highly developed areas of the watershed. The temperature of the Tankerhoosen River or its tributaries did not exceed the established limit of 85ºF (approximately 29 degrees Celsius) contained in the Connecticut Water Quality Standards (referred to as CT WQS hereafter) during any of the monitoring events. Measured ph values (Figure 2-2) throughout the Tankerhoosen River watershed were generally within the CT WQS range, except along Gages Brook where the measured ph was slightly below 6.5 on several occasions. The ph of Gages Brook is generally more variable and somewhat lower than elsewhere in the watershed. F:\P2005\0257\A10\TWS report doc 11

15 Dry - Nov. 05 Wet - Aug. 06 Wet - Oct. 06 Dry - Oct. 06 CT WQS: Std. Units 8.00 ph GB1 GB4 GB3 GB2 GB5 TR1 TR2 Location RB1 CB1 TR4 TR5 Figure 2-2: Water ph Tankerhoosen River Watershed TR Dry - Nov. 05 Wet - Aug. 06 Dissolved Oxygen (mg/l) CTWQS: 5 mg/l GB1 GB4 GB3 GB2 GB5 TR1 TR2 Location RB1 CB1 TR4 TR5 Figure 2-3: Dissolved Oxygen - Tankerhoosen River Watershed TR6 F:\P2005\0257\A10\TWS report doc 12

16 Dissolved oxygen measured throughout the watershed (Figure 2-3) was consistently above the 5 mg/l standard during the monitoring events. Dissolved oxygen was lowest along Gages Brook, although not below 84% of saturation and well above the 5 mg/l standard. Note that the dissolved oxygen measurements during the wet and dry weather monitoring events in October 2006 are not presented in Figure 2-3 because these data are of uncertain quality due to calibration issues with the dissolved oxygen meter for these events. Specific Conductivity The conductivity of rivers in the United States generally ranges from 0.05 to 1.50 ms/cm. Conductivity outside this range could indicate that the water is not suitable for certain species of fish or macroinvertebrates. Figure 2-4 presents the range of specific conductivity readings measured in the Tankerhoosen River watershed. Readings tend to increase downstream along the Tankerhoosen River during wet weather events; however even these measurements are still within an acceptable range Dry - Nov. 05 Wet - Aug. 06 Wet - Oct. 06 Dry - Oct. 06 Specific Conductivity (ms/cm) GB1 GB4 GB3 GB2 GB5 TR1 TR2 RB1 CB1 TR4 TR5 TR6 Figure 2-4: Specific Conductivity - Tankerhoosen River Watershed Turbidity and Total Suspended Solids Figure 2-5 and Figure 2-6 summarize average annual turbidity and total suspended solids (TSS), respectively, measured at locations throughout the watershed. Note that Figure 2-5 excludes nondetect values (i.e., values below the reported laboratory detection limit of 0.1 mg/l). Figure 2-5 also includes an EPA Reference Condition which has been derived as baseline criteria for each region of the U.S. The reference condition value shown on the figure (3.04 NTU) represents the 25th percentile of data from surface waters in the Eastern Coastal Plain Ecoregion (Ecoregion XIV) that are minimally impacted by human activities and believed to be protective of aquatic life and recreational uses. F:\P2005\0257\A10\TWS report doc 13

17 Dry - Nov. 05 Wet - Aug. 06 Wet - Oct. 06 Dry - Oct. 06 Turrbidity (NTU) EPA Reference Condition:3.04 NTU 0.00 GB1 GB4 GB3 GB2 GB5 TR1 TR2 RB1 CB1 TR4 TR5 TR6 Location Figure 2-5: Turbidity Tankerhoosen River Watershed Total Suspended Solids (mg/l) Dry - Nov. 05 Wet - Aug. 06 Wet - Oct. 06 Dry - Oct GB1 GB4 GB3 GB2 GB5 TR1 TR2 Location RB1 CB1 TR4 TR5 TR6 Figure 2-6: Total Suspended Solids Tankerhoosen River Watershed F:\P2005\0257\A10\TWS report doc 14

18 Turbidity and TSS were significantly higher during the wet weather monitoring events than during the dry weather events at nearly all of the monitoring locations. Turbidity rose dramatically during the August 2006 wet weather event, exceeding the EPA reference condition and CT WQS (ambient turbidity is assumed to be similar to dry weather turbidity levels) at nearly all locations. During the August 2006 wet weather monitoring event, turbidity measurements generally exhibited a declining trend from upstream to downstream within the watershed. The highest turbidity levels were measured along the Gages Brook tributary near I-84 (GB3 and GB4), with somewhat lower, although still elevated, concentrations measured in Gages Brook, the Tankerhoosen River downstream of Bolton Road, and in Clarks Brook downstream of Bolton Road and I-84, with progressively lower values in the lower reaches of the Tankerhoosen River. A comparison of the turbidity and TSS levels from the two wet weather monitoring events highlights the variability in wet weather concentrations for individual storms. While the August 2006 monitoring event resulted in significant turbidity exceedances of the EPA reference condition and CT WQS, the October 2006 wet weather event resulted in only a few exceedances of the EPA reference condition, with the highest values measured in the lower reaches of the Tankerhoosen River as compared to the August 2006 event in which the highest turbidity concentrations were measured upstream in the watershed. These differences may be due to differences in precipitation between the two storms, as well as the timing of sample collection relative to rainfall-runoff processes in the watershed. Although the peak rainfall intensities were similar for both storms, the August 2006 storm was longer in duration and more than twice the total precipitation of the October 2006 storm. Stream flows were likely higher for a longer duration during the August 2006 storm event. Stream channel erosion may be a potential source of the observed turbidity during the August 2006 wet weather monitoring event, in addition to stormwater runoff. Due to the ubiquitous nature of sediment sources in most developed watersheds, it is difficult to attribute the turbidity excursions to a particular source. However, based on the wet weather monitoring results, it is clear that excessive turbidity is a water quality issue in the Tankerhoosen River and its tributaries, particularly Gages Brook. The dry weather monitoring results suggest a modest dry weather source of turbidity in the lower reaches of the Tankerhoosen River downstream of Dobsonville Pond and in the vicinity of a stormwater basin associated with I-84. Total Coliforms and E. coli Elevated levels of indicator bacteria were measured at all monitoring locations during the October 2006 wet weather monitoring event. Figure 2-7 summarizes total coliform concentrations measured at each location. The CT WQS for total coliform (single sample maximum of 500 colonies/100 ml) is also included in the figure for reference. A log-scale is used for these plots to aid in visualizing the data. Measured total coliforms increased during the wet weather sampling event, most likely due to stormwater runoff and other non-point sources of bacteria (pet waste, waterfowl, septic systems, etc.). A similar trend was observed for E. coli (Figure 2-8), for which the CT WQS is a single sample maximum of 235 colonies/100 ml. F:\P2005\0257\A10\TWS report doc 15

19 Dry - Oct. 06 Wet - Oct. 06 Total Coliforms (Col/100 ml) 1000 CTWQS: 500 col/100 ml 1 GB1 GB4 GB3 GB2 GB5 TR1 TR2 RB1 CB1 TR4 Figure 2-7: Total Coliform - Tankerhoosen River Watershed TR5 TR Dry - Oct. 06 Wet - Oct. 06 E. coli (col/100 ml) GB1 GB4 GB3 GB2 GB5 TR1 TR2 RB1 CB1 TR4 TR5 TR6 Figure 2-8: E. coli - Tankerhoosen River Watershed CTWQS: 235 col/100 ml F:\P2005\0257\A10\TWS report doc 16

20 Dry weather exceedances of the CT WQS for total coliform also occurred at the Gages Brook monitoring location behind the Tolland Agricultural Center and at the Tankerhoosen River monitoring location just upstream of Fish and Game Road, which may be attributable to natural sources such as waterfowl or wildlife. Dry weather E. coli levels were measured above the CT WQS at only one location, near the mouth of the Tankerhoosen River. Note that indicator bacteria data collected during the November 2005 and August 2006 monitoring events are not presented in Figure 2-7 or Figure 2-8 due to inadequate dilutions of the samples, which resulted in unacceptably low reporting thresholds. Therefore, the indicator bacteria data from these two events were not included in the evaluation. Heavy Metals Figure 2-9 summarizes dissolved copper concentrations at watershed sampling locations relative to the CT WQS freshwater chronic aquatic life criterion of 4.8 micrograms per liter (ug/l). Biological integrity is impaired when the ambient concentration exceeds this value on more than 50 percent of days in any year (Connecticut Water Quality Standards, 2002). As depicted in Figure 2-9, during the wet weather monitoring event of August 2006, two exceedances of the chronic aquatic life criterion were measured at the Gages Brook monitoring location behind the Tolland Agricultural Center, as well as one exceedance at three of the four other monitoring locations along Gages Brook. This indicates a wet weather source of metals close to the I-84 crossing of Gages Brook, as the dissolved copper concentration was consistently below detection limits at the Gages Brook headwaters monitoring location (GB1). Additionally, the monitoring location along Clarks Brook (CB1) indicates a source of metals in this tributary. The relatively lower copper concentrations along the Tankerhoosen River are likely attributable to dilution effects. The data suggest that copper is a potential source of impairment in Gages Brook and Clarks Brook. The November 2005 results also indicate dry weather sources of dissolved copper at several of the Gages Brook monitoring locations. The highest dry weather copper concentration, which also exceeded the CT WQS freshwater chronic aquatic life criterion, was measured at the location behind the Tolland Agricultural Center, which suggests a significant dry weather source of metals between this location and the Gages Brook headwaters location. Industrial activity within the Tolland Industrial Park is a potential source of elevated metals in Gages Brook during dry weather. Additional monitoring is recommended upstream and downstream of the industrial park to further evaluate potential dry weather impacts and possible illicit connections/discharges from facilities in the industrial park. F:\P2005\0257\A10\TWS report doc 17

21 Dry - Nov. 05 Dry - Oct. 06 Wet - Aug. 06 Wet - Oct. 06 Copper (mg/l) CTWQS: mg/l (Chronic Aquatic Life Criterion) GB1 GB4 GB3 GB2 GB5 TR1 TR2 RB1 CB1 TR4 TR5 TR6 Figure 2-9: Dissolved Copper Tankerhoosen River Watershed Dry - Nov. 05 Dry - Oct. 06 Wet - Aug. 06 Wet - Oct Lead (mg/l) CTWQS: mg/l (Chronic Aquatic Life Criterion) 0 GB1 GB4 GB3 GB2 GB5 TR1 TR2 RB1 CB1 TR4 TR5 TR6 Figure 2-10: Lead Tankerhoosen River Watershed F:\P2005\0257\A10\TWS report doc 18

22 Figure 2-10 summarizes dissolved lead concentrations at watershed sampling locations relative to the CT WQS freshwater chronic aquatic life criterion of 1.2 micrograms per liter (ug/l). Biological integrity is impaired when the ambient concentration exceeds this value on more than 50 percent of days in any year (Connecticut Water Quality Standards, 2002). As depicted in Figure 2-10, during the August 2006 monitoring event, exceedances of the chronic aquatic life criterion were measured at four out of five monitoring locations along Gages Brook. Lead was only measurable once, during the dry sampling event of October 2006 at the Gages Brook location farthest upstream (GB1). Again, this result further supports the finding of a wet weather source of metals to Gages Brook. The highest wet weather lead concentration was measured in the Gages Brook monitoring location immediately downstream of I-84, which suggests that highway runoff is a likely source of metals to Gages Brook. Stormwater runoff associated with construction activity within the Gages Brook watershed may also be a potential source of elevated turbidity and other constituents, such as metals. Other tributaries with measured lead concentrations in excess of the CT WQS during the August 2006 sampling event include Clarks Brook (CB1) and Railroad Brook (RB1). Exceedances of the CT WQS were also measured along the Tankerhoosen River at the Fish and Game Road (TR1) and Bolton Road (TR2) monitoring locations. The relatively lower lead concentrations downstream are likely attributable to dilution effects. The data suggest that lead is a potential source of impairment in Gages Brook, Clarks Brook, and the Tankerhoosen River. Nitrogen The nitrogen species monitored during the study included ammonia, nitrate, and organic nitrogen. Total Nitrogen is a measure of the abovementioned nitrogen species, in addition to nitrite, which is rapidly converted to nitrate in surface waters. Even without the addition of nitrite, many of the monitoring locations exceeded the EPA recommended Total Nitrogen criterion for rivers in Ecoregion XIV of 0.71 mg/l. Nitrate is the dominant nitrogen species in the Tankerhoosen River and its tributaries, accounting for up to 84% of all nitrogen in samples collected at some locations. This reflects the significant contribution of nitrogen from sources in the watershed such as precipitation and atmospheric deposition, urban stormwater runoff, septic system effluent, agricultural runoff, and animal waste. Nitrogen concentrations were consistently higher at the Gages Brook monitoring locations than the other monitoring locations in both wet and dry weather. High levels of ammonia may pose a threat to aquatic life. Freshwater ammonia criteria (acute and chronic) are based on ph and the presence of salmonid and fish early life stages. As ph varies from sample to sample, so do the ammonia criteria. Ammonia concentrations are presented in Figure None of the samples exceeded the associated ammonia criteria. F:\P2005\0257\A10\TWS report doc 19

23 October 2006 Wet August Wet Ammonia Nitrate Organic Ammonia Nitrate Organic Nitrogen (mg/l) Nitrogen (mg/l) EPA Reference Condition: 0.71 mg/l TN November 2005 Dry October Dry Ammonia Nitrate Organic GB1 GB4 GB3 GB2 GB5 GB1 GB4 GB3 GB2 GB5 TR1 TR2 RB1 CB1 TR4 TR5 TR6 EPA Reference Condition: 0.71 mg/l TN TR1 TR2 RB1 CB1 TR4 TR5 TR Figure 2-11: Nitrogen Species Tankerhoosen River Watershed Nitrogen (mg/l) Nitrogen (mg/l) EPA Reference Condition: 0.71 mg/l TN GB1 GB4 GB3 GB2 GB5 TR1 TR2 RB1 CB1 TR4 TR5 TR6 Ammonia Nitrate Organic EPA Reference Condition: 0.71 mg/l TN GB1 GB4 GB3 GB2 GB5 TR1 TR2 RB1 CB1 TR4 TR5 TR6 F:\P2005\0257\A10\TWS report doc 20

24 Dry - Nov. 05 Dry - Oct. 06 Wet - Aug. 06 Wet - Oct. 06 Ammonia (mg/l) GB1 GB4 GB3 GB2 GB5 TR1 TR2 RB1 CB1 TR4 TR5 TR6 Figure 2-12: Ammonia - Tankerhoosen River Watershed Dry - Nov. 05 Dry - Oct. 06 Wet - Aug. 06 Wet - Oct Phosphorus (mg/l) EPA Reference Condition: GB1 GB4 GB3 GB2 GB5 TR1 TR2 RB1 CB1 TR4 TR5 TR6 Figure 2-13: Phosphorus Tankerhoosen River Watershed F:\P2005\0257\A10\TWS report doc 21

25 Phosphorus Total phosphorus concentrations measured throughout the watershed (Figure 2-13) are consistently above the EPA recommended Total Phosphorus criterion of 0.03 mg/l, which is also the CT WQS summer phosphorus concentration for lakes that would be expected to result in full support for contact recreational uses. Phosphorus concentrations measured during the wet weather event of August 2006 significantly exceeded the CT WQS and EPA criterion at most locations. Dry weather concentrations of phosphorus also exceeded the criterion at several of the Gages Brook monitoring locations, the Railroad Brook monitoring location, and the Tankerhoosen River downstream of Dobsonville Pond. The elevated phosphorus levels measured in this study are an indicator of potential organic enrichment and algal growth in water bodies along the Tankerhoosen River and its tributaries, which could impair aquatic life support and contact recreation under certain conditions. 2.3 Biological Monitoring Results Connecticut River Watch Program RBV Monitoring RBV monitoring results from the Connecticut River Watch Program since 2002 are summarized in Table 2-1, which includes the occurrence (percentage and total number) of different types of organisms in each RBV category by site. Sites with 1 to 3 organisms in the most wanted category the most sensitive to pollution are considered by DEP to have very good water quality; sites with 3 to 4 most wanted organisms are considered to have excellent water quality; and sites with 5 or more organisms in the most wanted category are considered to have exceptional water quality (Connecticut River Watch Program, Hockanum River Rapid Bioassessment Summary Report 2005, December 2006). It is important to note that while sites with 5 or more most wanted organisms are a strong indicator of aquatic life support, sites that have fewer than 3 most wanted organisms do not definitively indicate impairment or degradation, just that the additional most wanted organisms were not documented by volunteers using the RBV protocol. In these instances, DEP recommends conducting additional assessments to verify species present, determining possible impacts of upstream land use, and evaluating the possibility of errors in conducting the RBV (Connecticut River Watch Program, March 2005). The RBV protocol is intended as a screening tool and not a definitive assessment method. Among the Tankerhoosen River watershed monitoring locations evaluated, the best representation of most wanted organisms has historically been observed at the Bolton Road and Tunnel Road sites along the Tankerhoosen River, and at the Gages Brook site behind the Tolland Agricultural Center, although the results have varied from year to year. The fewest most wanted organisms have been observed at the Tankerhoosen River sites downstream of Dobsonville Pond and near the confluence with the Hockanum River. F:\P2005\0257\A10\TWS report doc 22

26 Table 2-1: RBV Benthic Macroinvertebrate Sampling Results Site ID Year River Location GB2 (HR7d) TR2 (HR7b) TR3 (HR7a) TR4 (HR7c) TR6 (HR7) Most Wanted Moderately Wanted Least Wanted Total # 2003 Gages Behind Tolland Agricultural 50% (6) 25% (3) 25% (3) 12 Center 2004 Gages Behind Tolland Agricultural 43% (3) 57% (4) 0% (0) 7 Center 2005 Gages Behind Tolland Agricultural Center 20%(1) 60%(3) 20%(1) 5 Behind Tolland 2006 Gages Agricultural 20% (2) 60% (6) 20% (2) 10 Center 2002 Tankerhoosen Bolton Rd. 50% (6) 50% (6) 0% (0) Tankerhoosen Bolton Rd. 40% (4) 50% (5) 10% (1) Tankerhoosen Bolton Rd. 14% (1) 72% (5) 14% (1) Tankerhoosen Bolton Rd. 22% (2) 67% (6) 11% (1) Tankerhoosen Bolton Rd. 40% (4) 60% (6) 0% (0) Tankerhoosen Tunnel Rd. 47% (8) 29% (5) 24% (4) Tankerhoosen Tunnel Rd. 41% (5) 41% (5) 17% (2) Tankerhoosen Tunnel Rd. 60% (3) 40% (2) 0% (0) Tankerhoosen Tunnel Rd. 50%(2) 50%(2) 0% (0) Tankerhoosen Tunnel Rd. 25% (2) 63% (5) 12% (1) Tankerhoosen Dobsonville Pond (downstream) 20% (2) 60% (6) 20% (2) Tankerhoosen Dobsonville Pond (downstream) 0%(0) 100%(4) 0%(0) Tankerhoosen Dobsonville Pond (downstream) 17% (1) 66% (4) 17% (1) Tankerhoosen Golfland, near confluence 15% (2) 46% (6) 39% (5) Tankerhoosen Golfland, near confluence 31% (4) 31% (4) 38% (5) Tankerhoosen Golfland, near confluence 13% (1) 50% (4) 37% (3) Tankerhoosen Golfland, near 14%(1) 72%(5) 14%(1) Tankerhoosen confluence Golfland, near confluence 14% (1) 72% (5) 14% (1) 7 Notes: 1. Sites with 1-3 organisms in the most wanted category the most sensitive to pollution are considered by DEP to have very good water quality; sites with 3-4 most wanted organisms are considered to have excellent water quality; and sites with 5 or more organisms in the most wanted category are considered to have exceptional water quality. 2. Site ID includes the 2006 Fuss & O Neill study site ID, followed by the previous RBV site ID in parentheses. F:\P2005\0257\A10\TWS report doc 23

27 2.3.2 Tankerhoosen River State of the Watershed Assessment Benthic macroinvertebrate surveys were also conducted in 2004 by Jane Seymour, Wildlife Consultant, as part of a State of the Watershed Assessment of the Tankerhoosen River Watershed undertaken by the Vernon Conservation Commission, in partnership with the Friends of the Hockanum River Linear Park of Vernon, Inc. and the Hockanum River Watershed Association. Riffle dwelling stream invertebrates were collected to assess stream quality. Invertebrates were collected in the upper Tankerhoosen River on the Tancanhoosen LLC property, in Barrows Brook, and in the unnamed tributary that drains into Gages Brook just upstream from Walker s Reservoir East. The RBV protocol was used to categorize and assess the benthic macroinvertebrates found at these locations. Three of the most wanted invertebrates were collected in the upper Tankerhoosen River site, just upstream from Fish and Game Road. Five moderately wanted were collected at this site. No least wanted invertebrates were collected. These results indicate high water quality at this site. Three of the most wanted invertebrates were collected at Barrow s Brook, two moderately wanted, and one of the least wanted. Additional invertebrates were collected that also indicate high water quality at this site. At the third site, the unnamed tributary of Gages Brook, no most wanted invertebrates were collected. Two moderately wanted and two least wanted invertebrates were collected. This site is just downstream of I-84. The lack of most wanted invertebrates at this site may be a result of impacts from I-84, although additional sampling at this location was recommended to further assess potential highway impacts on the stream (Seymour, 2004) Fuss & O Neill Rapid Bioassessment In October 2006, Fuss & O'Neill conducted field surveys of the benthic macroinvertebrates and physical habitat of selected locations along the Tankerhoosen River and its tributaries following the EPA Rapid Bioassessment Protocol. The protocol included laboratory processing of macroinvertebrate samples under controlled conditions by Aquatec Biological Sciences, Inc. A list of the organisms found at each site is included in Appendix D. The October 2006 Fuss & O Neill bioassessment results, together with the October 2006 RBV bioassessment results, are summarized in Table 2-2. The 2006 bioassessment data vary considerably by site, but generally indicate very good water quality at most of the monitoring locations, with the exception of the lower Tankerhoosen River near the confluence with the Hockanum River (TR6) and downstream of Dobsonville Pond (TR4). A greater number of least wanted organisms were observed at many of the monitored locations, including most of the Gages Brook locations (GB1, GB3, and GB4), several of the Tankerhoosen River locations (TR1 and TR5), and the Clarks Brook and Railroad Brook locations. Although higher representation of organisms in the most wanted category the most sensitive to pollution is an indicator of better water quality, in general, streams with representation from all RBV categories indicate good water quality (Connecticut River Watch Program, Hockanum River Rapid Bioassessment Summary Report 2005, December 2006). To further characterize the Fuss & O Neill bioassessment monitoring data, the following biological measures were calculated for each site (Table 2-3): F:\P2005\0257\A10\TWS report doc 24