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MPDES Permit # MTR04005 Evaluation of Stormwater Quality Monitoring 2018 Sample Results Introduction The City of Kalispell operates its storm drainage system under the authorization of the Montana Pollution Discharge Elimination System (MPDES) General Permit for Storm Water Discharges Associated with Small Municipal Separate Storm Sewer Systems (MS4s). The current MS4 General Permit, issued by the Montana Department of Environmental Quality (MDEQ), is effective from January 1, 2017 through December 31, 2021. Part IV of the MS4 General Permit requires semi-annual monitoring (self-monitoring). The City has selected self-monitoring Option 2 (see Part IV of the MS4 General Permit). Stormwater grab samples were collected semi-annually from four stormwater discharge locations within the City of Kalispell. Four discharge sample locations were chosen to represent stormwater runoff from a primarily commercial/industrial area, from a primarily residential area, from a large drainage area combining both commercial and residential areas, and upstream, outside the MS4 boundary to evaluate water quality entering the MS4 (Table Table 1. Self-monitoring sample locations Name Watershed Receiving Waterbody Location Drainage Area (Acre) Frequency Sample Parameters 001 SWR-4 Stillwater River 48°11’40.14”N 114°17’55.76”W 266 Semi- annual Total Suspended Solids Chemical Oxygen Demand Total Phosphorus Total Nitrogen pH Copper Lead Zinc Estimated Flow Oil and Grease 002 SWR-7 Stillwater River 48°12’26.98”N 114°18’49.81”W 100 Semi- annual 003 AC-A Ashley Creek 48°11’35.66”N 114°20’40.76”W NA Semi- annual 004 AC-11 Ashley Creek 48°11’10.01”N 114°19’17.46”W 294 Semi- annual ---PAGE BREAK--- 2 Methods Sample Collection Grab samples were collected once in the fall (4/13/18) and once in the spring (11/2/18) of 2018. Field personnel collected samples during rainfall events that produced a measurable volume of runoff flowing past/through the monitoring locations that allowed a sample to be collected. Clean, labeled bottles provided by the laboratory, on an extension pole, were used to obtain stormwater samples. Field logs were used to document the date, time, location, personnel, weather, conditions observed, samples collected, estimated duration of the storm event, and total rainfall of the storm event. Sample Parameters and Analytical Methods Stormwater samples were analyzed for the parameters listed in Table 1. Table 2 shows the parameters and the standard analytical methods used. Montana Environmental Labs processed all the samples and uses a combination of blanks, laboratory control spikes, surrogates, and duplicates to evaluate analytical results. Chain of custody forms accompanied all samples. Sample Analysis Due to new sample locations being designated in 2017, statistical analyses are not appropriate because of the low number of samples. The City of Kalispell is required to calculate the long- term median concentration of all known monitoring results at an individual location of each parameter in Table 1 Par IV.A. of the MS4 General Permit issued by MDEQ. To compare individual parameters across locations, bar charts were created to visually represent the sample values of 2018 in comparison to the long-term median. To compare parameters at one location, parameter values were standardized and graphed over time by location. The MS4 General Permit requires monitoring results to be used to evaluate measures taken to improve the quality of stormwater discharges. This includes an evaluation of the results relative to the long-term median, comparisons between monitoring locations, discussion of trends and outliers compared to the long-term median, discussion of pH values outside the range of 6.0 to 9.0, and a schedule and rationale for BMPs planned to improve water quality of stormwater discharges based on monitoring results. ---PAGE BREAK--- 3 Table 2. Parameters and standard analytical methods Parameter Analytical Method Reporting Limit (mg/L) Sample Container Preservative Holding Time (days) Total Suspended Solids SM 2450 D 1 1 L plastic 2 None 2 Analyze immediately 2 Total Phosphorus E365.1 0.01 Nitrogen – Kjeldahl, total 1 E351.2 0.2 Nitrate & Nitrite, total 1 E353.2 E300A 0.01 Chemical Oxygen Demand E410.1 E410.4 1 Total Recoverable Copper E200.8 0.01 Total Recoverable Lead E200.8 0.001 Total Recoverable Zinc E200.7 E200.8 0.01 Oil and Grease E1664A 1 1 L glass H2SO4 to pH<2 Cool to 4°C 28 Estimated Flow NA NA NA NA Analyze onsite 3 Dissolved Oxygen SM 4500-OG 0.1 NA NA Analyze onsite 3 Temperature NA 0.1°C NA NA Analyze onsite 3 pH E150.1 0.1 unit NA NA Analyze onsite 3 1 Total Nitrogen is calculated from Nitrogen – Kjeldahl, total and Nitrate & Nitrite, total. 2 Samples will be immediately delivered to the Montana Environmental Lab in Kalispell. The lab staff will separate the 1L samples so that each parameter can be analyzed. Preservatives will be added by the lab staff, if necessary. 3 The City analyze for estimated flow, dissolved oxygen, temperature, and pH, onsite. ---PAGE BREAK--- 4 Results Sample Comparison and Median Concentration Table 3 is a summary of the 2018 sample parameter comparisons with the long-term median concentrations for each. Long-term median concentrations are calculated from all known monitoring results for each parameter at a monitoring location. Please note, as monitoring locations were new in 2017, median concentrations have been calculated only with samples taken since 2017 (4 total samples per site). Figures 1-9 visually depict observed and median parameter concentrations by site location. Many of the sites had higher recorded parameter values in spring than fall. TSS, copper, lead, and zinc were greater for all stormwater sampling locations collected in the spring (heavy metals were not detected at AC-A/003, the in-stream sample). Chemical oxygen demand was greater in the spring for all locations except for AC-11/004. Total phosphorous was greater in the spring for all locations except SWR-2/002 where it was equivalent for both sampling events. Oil and grease values were greater in the spring at both locations discharging to the Stillwater River (SWR- 4/001, SWR-7/002) and equivalent in spring and fall for AC-A/003 and AC-11/004. Total nitrogen was greater in spring for AC-A/003 and AC-11/004 and greater in fall for SWR-4/001 and SWR- 7/002. Flow was greater in spring and pH was greater in fall for all locations. In the spring, observed parameter values were notably elevated at AC-11/004 for total phosphorus and at SWR-4/001 for total suspended solids, oil/grease, and COD. ---PAGE BREAK--- 5 Table 3. 2018 Parameter Comparison ND=Not detected at the reporting limit ---PAGE BREAK--- 6 Figure 1. Observed (2018) and median (2017-2018) TSS (total suspended solids) concentrations by location. Horizontal red lines represent median concentrations. Y-axis is on a log scale. Figure 2. Observed (2018) and median (2017-2018) COD (chemical oxygen demand) concentrations by location. Horizontal red lines represent median concentrations. 1 10 100 1000 SWR-4 (4/13/2018) SWR-4 (11/2/2018) SWR-7 (4/13/2018) SWR-7 (11/2/2018) AC-A (4/13/2018) AC-A (11/2/2018) AC-11 (4/13/2018) AC-11 (11/2/2018) TSS (mg/L) - Log Scale LOCATION OBSERVED & MEDIAN TSS 0 100 200 300 400 500 600 700 SWR-4 (4/13/2018) SWR-4 (11/2/2018) SWR-7 (4/13/2018) SWR-7 (11/2/2018) AC-A (4/13/2018) AC-A (11/2/2018) AC-11 (4/13/2018) AC-11 (11/2/2018) COD (mg/L) LOCATION OBSERVED & MEDIAN COD ---PAGE BREAK--- 7 Figure 3. Observed (2018) and median (2017-2018) TP (total phosphorus) concentrations by location. Horizontal red lines represent median concentrations. Figure 4. Observed (2018) and median (2017-2018) TN (total nitrogen) concentrations by location. Horizontal red lines represent median concentrations. 0 1 2 3 4 5 6 7 8 SWR-4 (4/13/2018) SWR-4 (11/2/2018) SWR-7 (4/13/2018) SWR-7 (11/2/2018) AC-A (4/13/2018) AC-A (11/2/2018) AC-11 (4/13/2018) AC-11 (11/2/2018) TP (mg/L) LOCATION OBSERVED & MEDIAN TP 0 0.5 1 1.5 2 2.5 3 SWR-4 (4/13/2018) SWR-4 (11/2/2018) SWR-7 (4/13/2018) SWR-7 (11/2/2018) AC-A (4/13/2018) AC-A (11/2/2018) AC-11 (4/13/2018) AC-11 (11/2/2018) TN (mg/L) LOCATION OBSSERVED & MEDIAN TN ---PAGE BREAK--- 8 Figure 5. Observed (2018) and median (2017-2018) pH concentrations by location. Horizontal red lines represent median concentrations. Figure 6. Observed (2018) and median (2017-2018) oil and grease concentrations by location. Horizontal red lines represent median concentrations. 6.5 6.7 6.9 7.1 7.3 7.5 7.7 7.9 8.1 8.3 8.5 SWR-4 (4/13/2018) SWR-4 (11/2/2018) SWR-7 (4/13/2018) SWR-7 (11/2/2018) AC-A (4/13/2018) AC-A (11/2/2018) AC-11 (4/13/2018) AC-11 (11/2/2018) pH LOCATION OBSERVED & MEDIAN PH 0 5 10 15 20 25 30 SWR-4 (4/13/2018) SWR-4 (11/2/2018) SWR-7 (4/13/2018) SWR-7 (11/2/2018) AC-A (4/13/2018) AC-A (11/2/2018) AC-11 (4/13/2018) AC-11 (11/2/2018) OIL & GREASE (mg/L) LOCATION OBSERVED & MEDIAN OIL & GREASE ---PAGE BREAK--- 9 Figure 7. Observed (2018) and median (2017-2018) copper concentrations by location. Horizontal red lines represent median concentrations. Figure 8. Observed (2018) and median (2017-2018) lead concentrations by location. Horizontal red lines represent median concentrations. 0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 SWR-4 (4/13/2018) SWR-4 (11/2/2018) SWR-7 (4/13/2018) SWR-7 (11/2/2018) AC-A (4/13/2018) AC-A (11/2/2018) AC-11 (4/13/2018) AC-11 (11/2/2018) COPPER (mg/L) LOCATION OBSERVED & MEDIAN COPPER 0 0.005 0.01 0.015 0.02 0.025 SWR-4 (4/13/2018) SWR-4 (11/2/2018) SWR-7 (4/13/2018) SWR-7 (11/2/2018) AC-A (4/13/2018) AC-A (11/2/2018) AC-11 (4/13/2018) AC-11 (11/2/2018) LEAD (mg/L) LOCATION OBSERVED & MEDIAN LEAD ---PAGE BREAK--- 10 Figure 9. Observed (2018) and median (2017-2018) zinc concentrations by location. Horizontal red lines represent median concentrations. Standardized Parameter Concentrations by Location Figures 10-13 compare sample parameters at one site over time. Parameters have been standardized to make the variables comparable. At most locations, many parameters co-vary together. Stormwater sample locations (SWR- 4/001, SWR-7/002, AC-11/004) appear to largely have elevated values in spring and lower values in fall. The parameter values at the in-stream location (AC-A/003), generally, do not fluctuate as much as the stormwater samples. The elevated TSS and oil and grease at SWR-4/001 on 4/13/18 appear to strongly co-vary, while the elevated TP at AC-11/004 does not strongly co-vary with any other parameters. 0 0.05 0.1 0.15 0.2 0.25 0.3 SWR-4 (4/13/2018) SWR-4 (11/2/2018) SWR-7 (4/13/2018) SWR-7 (11/2/2018) AC-A (4/13/2018) AC-A (11/2/2018) AC-11 (4/13/2018) AC-11 (11/2/2018) ZINC (mg/L) LOCATION OBSERVED & MEDIAN ZINC ---PAGE BREAK--- 11 Figure 10. Standardized parameter concentrations over time at SWR-4/001. Figure 11. Standardized parameter concentrations over time at SWR-7/002. -2 -1 0 1 2 3 4 S W R- 4 (6 / 1 3 / 2 0 1 7 ) S W R- 4 (11/ 22/ 2017) S W R- 4 13/ 2018) S W R- 4 (11/ 2/ 2018) NORMALIZED PARAMETER VALUES SWR-4 - RESIDENTIAL 30%, COMMERCIAL 70% TSS (mg/L) pH TP (mg/L) COD (mg/L) TN (mg/L) Copper (mg/L) Lead (mg/L) Zinc (mg/L) Oil & Grease (mg/L) Flow (GPM) -2 -1 0 1 2 3 4 S W R- 7 (6 / 1 3 / 2 0 1 7 ) S W R- 7 (11/ 22/ 2017) S W R- 7 13/ 2018) S W R- 7 (11/ 2/ 2018) NORMALIZED PARAMETER VALUES SWR-7 - COMMERICAL/INDUSTRIAL TSS (mg/L) pH TP (mg/L) COD (mg/L) TN (mg/L) Copper (mg/L) Lead (mg/L) Zinc (mg/L) Oil & Grease (mg/L) Flow (GPM) ---PAGE BREAK--- 12 Figure 12. Standardized parameter concentrations over time at AC-A/003. Figure 13. Standardized parameter concentrations over time at AC-11/004. -2 -1 0 1 2 3 4 A C - A (6 / 1 3 / 2 0 1 7 ) A C - A (11/ 22/ 2017) A C - A 13/ 2018) A C - A (11/ 2/ 2018) NORMALIZED PARAMETER VALUES AC-A - IN-STREAM TSS (mg/L) pH TP (mg/L) COD (mg/L) TN (mg/L) Copper (mg/L) Lead (mg/L) Zinc (mg/L) Oil & Grease (mg/L) Flow (GPM) -2 -1 0 1 2 3 4 A C - 1 1 (6 / 1 3 / 2 0 1 7 ) A C - 1 1 (11/ 22/ 2017) A C - 11 13/ 2018) A C - 11 (11/ 2/ 2018) NORMALIZED PARAMETER VALUES AC-11 - RESIDENTIAL TSS (mg/L) pH TP (mg/L) COD (mg/L) TN (mg/L) Copper (mg/L) Lead (mg/L) Zinc (mg/L) Oil & Grease (mg/L) Flow (GPM) ---PAGE BREAK--- 13 Discussion: Trends, Outliers, and BMPs The following analysis reviews the 2018 parameter trends and outliers compared to the calculated long-term median and examines results outside a pH range of 6.0 to 9.0 standard units. Additionally explained is a schedule and rationale for BMPs planned to improve the water quality of stormwater discharges based on monitoring results. Sampling Conditions Spring samples were collected in April 2018. The winter leading up to this sample collection had numerous snow events, which lead to frequent sanding and salt application. Fall samples were collected in November 2018. Prior to sample collection, there was a dry summer followed by several rain events that were either too small to obtain the adequate amount of flow or occurred outside of work hours. Spring samples generally had higher concentrations of all parameters. This same pattern was observed in the 2017 sample results. This may be indicative of winter loading of contaminants. Additional measures to try and reduce spring runoff may be beneficial. Future sampling will help clarify trends and what BMPs will be most beneficial to minimize pollutant discharge. Stillwater River Two locations drain into the Stillwater River, which is listed as impaired for sediment. Location 001-SWR-4 is characterized as mixed residential (30%) and commercial (70%) and location 002- SWR-7 is characterized as commercial/industrial. Mixed Residential (30%) and Commercial (70%) Location Sample location 001-SWR-4 drains about 266 acres and had elevated total suspended solids, oil/grease, and chemical oxygen demand in the spring sample. The lab that processes the samples provided a note that the two sample bottles provided appeared visually different and a duplicate was run of oil and grease. The first analysis found 24 mg/L (reported) while the second analysis found 3 mg/L. The inconsistency indicates a potential error in sample collection or sample processing. Due to the elevated TSS and oil and grease, the surrounding storm system was inspected and cleaned. This sample location is from two mechanical treatment units. Both treatment units were cleaned along with upstream manholes and sumps (if needed). A role of Ram-Nek/manhole mastic was found in a manhole sump upstream and was removed. This could have been contributing to higher oil and grease and COD readings. The cleaning schedule of the two treatment unites was updated to twice a year due to the amount of debris found when they were cleaned. After cleaning, TSS, oil and grease, and COD levels dropped during the next sampling event. Commercial/Industrial Location At sample location 002-SWR-7, the median of every parameter, except TP and TN, was higher than other locations. The drainage area of 002-SWR-7 is approximately 100 acres and is comprised mostly of commercial/industrial land use including highway managed by Montana Department of Transportation. Activities in industrial areas and highways, ---PAGE BREAK--- 14 including material handling and storage, equipment maintenance and cleaning, and others, are often exposed to weather and may introduce pollutants into stormwater. Total suspended solids and chemical oxygen demand readings were elevated, though not as high as 001-SWR-4. All parameters will be monitored to try and further understand sources. Future sampling may help clarify if these are trends or outliers at this location and what management practices will best serve for a reduction of the pollutant loads. The City’s Capital Improvement Program has a stormwater quality treatment facility planned for 2020 to try and reduce the MS4’s discharge of sediment to the Stillwater River. Samples collected prior to implementation may provide information on BMP effectiveness in a commercial/industrial location and help plan future BMPs in other commercial/industrial areas. Ashley Creek Two locations drain into Ashley Creek, which is listed as impaired for phosphorus, nitrogen, dissolved oxygen, sediment, and temperature. Location 003-AC-A is characterized as being in- stream and outside the MS4 boundary and 004-AC-11 is characterized as residential. In-Stream Outside MS4 Boundary Location Sample location 003-AC-A did not have notable trends or outliers in monitoring results compared to the calculated long-term median. The in-stream sample results provide background readings of the pollutants in-stream during comparable rain events. Residential Location The drainage area of 004-AC-11 is approximately 300 acres, comprised mostly of residential land use. Sample location 004-AC-11 results showed elevated total suspended sediment, chemical oxygen demand, total phosphorus, and total nitrogen. Total phosphorus was significantly elevated in the spring sample. Future sampling may help clarify if these are trends or outliers at this location and what management practices will best serve for a reduction of the pollutant loads. The City’s Capital Improvement Program has a stormwater quality treatment facility planned for 2023 to try and reduce the MS4’s discharge of pollutants to Ashley Creek. Samples collected prior to implementation may provide information on BMP effectiveness in a residential location and help plan future BMPs in other residential areas. Identified Pollutants Several pollutants were identified as elevated through this evaluation. As such, this section provides a schedule and rationale of BMPs planned to improve the water quality of the stormwater discharges. ---PAGE BREAK--- 15 Chemical Oxygen Demand (COD) Potential Sources Natural: • Leaves and woody debris • Dead plants and animals • Animal manure Industrial: • Oils and grease from transportation and industrial/commercial site activities • Benzene from gasoline • detergents • Pesticides • Herbicides • Wood preservatives • organic industrial chemicals Residential: • Grass clippings and leaves • Animal waste • Failing septic systems • Sugar-containing substances (milk, molasses, juice, vegetables, energy drinks, etc.) Management Measures and BMPs Table 4 outlines the potential sources, reasons, and management measures the City has or will implement for the MPDES MS4 permit. Dry weather screening will continue to be utilized to aid in identifying sources of chemical oxygen demand. Additionally, two locations have a planned stormwater quality treatment facility in the City’s Capital Improvement Program. Table 4. COD Evaluation Potential Sources Reasons *Minimum Measure BMP Date(s) Implemented Organic material i.e. leaves, grass clippings Fallen Leaves Landscaping Pre-Winter Maintenance 1 Public Education Program 2015-Current 6 Implement Pollution Prevention Good Housekeeping Guidance Manual for Kalispell Municipal Operations. Provide training to City employees. 2015-Current Street Sweeping Program 2015-Current Leaf Collection Program 2015-Current Storm Drainage System Inspection and Cleaning 2015-Current Residential Curbside Pickup Services 2013-Current * Minimum Measures 1) Public education and outreach on stormwater impacts; 2) Public involvement/participation; 3) Illicit discharge detection and elimination; 4) Construction site stormwater runoff control; 5) Post-construction stormwater management in new development and redevelopment; and, 6) Pollution prevention and good housekeeping for municipal operations. ---PAGE BREAK--- 16 Total Suspended Solids (TSS) Potential Sources Natural: • Erosion Industrial: • Land development • Roadway material deterioration • Road salt and sand • Road paint • Industrial/commercial site activities • Gravel parking areas Residential: • Land development • Road salt and sand • Road paint • Roadway material deterioration Management Measures and BMPs Table 5 outlines the potential sources, reasons, and management measures the City has implemented or will implement for the MPDES MS4 General Permit. Additionally, two locations have a planned stormwater quality treatment facility in the City’s Capital Improvement Program. ---PAGE BREAK--- 17 Table 5. TSS Evaluation Potential Sources Reasons *Minimum Measure BMP Date(s) Implemented Construction Site Runoff Subdivision Development Residential House Construction Municipal Operations Commercial Development 4 Ordinance 1600: Regulating land disturbance in City limits. Requires construction site Stormwater Management Permits for all land disturbance within City limits. 2015- Current Provide training for builders, engineers, and developers. 2015- Current 1 Public Education Program 2015- Current Public Education Program 2010 Update to include commercial education. 2010- Current 6 Implement Pollution Prevention Good Housekeeping Guidance Manual for Kalispell Municipal Operations. Provide training to City employees. 2015- Current Sand on Roads Winter condition road sanding 6 Implement Pollution Prevention Good Housekeeping Guidance Manual for Kalispell Municipal Operations. Provide training to City employees. 2015- Current Street Sweeping 2015- Current Storm Drainage System Inspection & Cleaning 2015- Current Industrial Site Activities Generation of solid material from industrial and commercial site activities 1 Public Education Program 2015- Current Industrial Site Activities Industrial and Commercial Sites Generation of solid material from industrial and commercial site activities Dirt/gravel driveways and parking areas 3 Illicit Discharge, Detection, and Elimination Program 2015- Current 5 Redevelopment standards implemented through Kalispell Design and Construction Standards 2015- Current Residential Yard Waste Management Native Landscaping Better Car and Equipment Washing 1 Public Education Program 2018- Current 6 Residential Curbside Pickup Services 2013- Current * Minimum Measures 1) Public education and outreach on stormwater impacts; 2) Public involvement/participation; 3) Illicit discharge detection and elimination; 4) Construction site stormwater runoff control; 5) Post-construction stormwater management in new development and redevelopment; and, 6) Pollution prevention and good housekeeping for municipal operations. ---PAGE BREAK--- 18 Oil and Grease Potential Sources Natural: Petroleum Industrial: Automotive oils Residential: Automotive oils Cooking oils Management Measures and BMPs Table 6 outlines the potential sources, reasons, and management measures the City has implemented or will implement for the MPDES MS General Permit. Additionally, two locations have a planned stormwater quality treatment facility in the City’s Capital Improvement Program. Table 6. Oil and Grease Evaluation Potential Sources Reasons *Minimum Measure BMP Date(s) Implemented Industrial Site Activities Common industrial and commercial site activities 1 Public Education Program 2007-Current Public Education Program 2010 Update to include commercial education 2010-Current 3 Illicit Discharge, Detection, and Elimination Program 2008-Current Restaurants Common restaurant activities 1 Public Education Program 2013-Current Residential Car Maintenance 1 Public Education Program 2018-Current * Minimum Measures 1) Public education and outreach on stormwater impacts; 2) Public involvement/participation; 3) Illicit discharge detection and elimination; 4) Construction site stormwater runoff control; 5) Post-construction stormwater management in new development and redevelopment; and, 6) Pollution prevention and good housekeeping for municipal operations. ---PAGE BREAK--- 19 Total Phosphorous Potential Sources Natural: Soil and rocks Plant and leaf litter Industrial: Fertilizers Waste Water Treatment Plant discharges Livestock and farm animals Commercial cleaning preparations Road salt Residential: Fertilizers Failing septic systems Pet waste Disturbed land areas Road salt Plant and leaf litter Management Measures and BMPs Table 7 outlines the potential sources, reasons, and management measures the City has implemented or will implement for the MPDES MS General Permit. Additionally, two locations have a planned stormwater quality treatment facility in the City’s Capital Improvement Program. Table 7. Total Phosphorous Evaluation Potential Sources Reasons *Minimum Measure BMP Date(s) Implemented Fertilizer Fall fertilizing of residential yards and commercial landscape area Fertilization storage, handling, and application 1 Public Education Program 2007-Current Organic material i.e. leaves, grass clippings Fallen leaves Landscaping Pre-Winter Maintenance Yard Waste Management 6 Street Sweeping Program 2011-Current Leaf Collection Program 2011-Current Storm Drainage System Inspection and Cleaning 2012-Current Review and update City Operational and Maintenance Activities as necessary. Provide training to City employees. 2007-Current Residential Curbside Pickup Services 2013-Current Litter and animal waste Pet waste 1 Public Education Program 2007-Current ---PAGE BREAK--- 20 APPENDIX A. Monitoring Parameters The parameters required to be monitored can contribute to stormwater pollution. The following is a description of the potential sources of stormwater runoff contamination. Total Suspended Solids (TSS) TSS is a common stormwater pollutant and can be generated from construction sites, bare spots in lawns and gardens, wastewater from washing/trucks on driveways and parking lots, dirt roads and driveways, and sanding roads during winter conditions. Chemical Oxygen Demand (COD) Organic material such as leaves, grass, oils, grease, and litter become deposited in urban areas and become part of stormwater runoff flows. A COD test can be used to quantify the amount of organics in water. COD is a measure of the capacity of water to consume oxygen during the decomposition of organic matter and the oxidation of inorganic chemicals such as Ammonia and nitrite. High COD concentrations lower dissolved oxygen concentration, progressively deteriorating conditions for fish and other aquatic life. Also, the absence of dissolved oxygen could result in the growth of microorganisms that produce by-products which cause foul odors in the water. Total Phosphorus (TP) Nutrients such as phosphorus are common constituents of nonpoint source runoff. The introduction of nutrients into receiving waters stimulates the growth of algae and other aquatic plants causing algal blooms and creating turbid conditions. Total phosphorus enters runoff from sources such as fertilizers, pesticides, grass clippings/leaves left on streets and sidewalks, detergents and washing fluids, animal waste, and seepage from septic tanks. Automobile lubricant emissions, food products, and various household cleaners, paints, fabrics and carpets contain phosphates which can also be transported by runoff. Total Nitrogen (TN) Plant nutrients, such as nitrogen, are common constituents of nonpoint source runoff. The introduction of nutrients into receiving waters stimulates the growth of algae and other aquatic plants causing algal blooms and creating turbid conditions. Total nitrogen enters runoff from sources such as fertilizers, grass clippings and leaves left on streets and sidewalks, detergents and washing fluids, animal wastes, and seepage from septic tanks. pH Most discharge flow types are neutral, having a pH value around 7, although groundwater concentrations can be somewhat variable. pH is a reasonably good indicator for liquid wastes from industries, which can have very high or low pH (ranging from 3 to 12). The pH of residential wash water tends to be rather basic (pH of 8 or Although pH data is often inconclusive by itself, it can identify problem outfalls that merit follow-up investigations using indicators that are more effective. Heavy Metals: Total Copper (Cu), Lead (Pb), Zinc (Zn) Metal pollutants can be generated from the operation and maintenance of motor vehicles, the degradation of highway material, and industrial/commercial site activities. Heavy metals in ---PAGE BREAK--- 21 water can cause bioaccumulation in animal tissues, affect reproduction rates and life spans of aquatic species, and ultimately affect recreational and commercial fisheries. Transportation- related sources of Zn include diesel fuel, crankcase and lubrication oils, grease, and decorative and protective coatings. Copper in stormwater runoff can be generated from wear on brake pads, roofing and gutter runoff, and copper-based fungicides/fertilizers used for controlling algae, fungi, and mildew. Metal finishers, electroplaters, and semiconductor manufacturers may use copper-containing materials in their manufacturing processes. Vehicle services (engine repair and service, fueling, vehicle body repair, replacement of fluids, recycling, cleaning, and outdoor equipment storage and parking through dripping engines) can generate toxic hydrocarbons and other organic compounds, oils and greases, nutrients, phosphates, heavy metals, paints and other contaminants. Radiator repair and flushing operations are the most likely source of copper- containing waste streams. The principal source of lead in highway and street stormwater runoff as well as soils in urban areas and near highways during the time of the NURP studies i.e., about 1980, was the use of lead as an additive in gasoline. Other sources of lead in stormwater runoff include yellow and white road marking paints used on parking lots, streets, buildings, building cavity dust and other demolition waste from buildings and structures, and vehicular sources including leaded petrol (auto exhaust), auto paint (which can still contain 10% lead), lead-acid batteries, lubricating oil and grease, and bearing wear. Oil and Grease (O&G) Oil and grease pollutants can be generated from leaks and spills of oil and gas, used oil dumping, and commercial and industrial activities. These organic pollutants cannot be easily decomposed through biological action and may persist for long periods. ---PAGE BREAK--- 22 APPENDIX B. Correlation Matrix Figure B1. Correlation matrix of water quality variables. Correlations are represented on the lower left, histograms on the diagonal, and xy plots on the upper right. TSS = total suspended solids, COD = chemical oxygen demand, TP = total phosphorus, TN = total nitrogen, CU = total copper, Pb = total lead, Zn = total zinc, OG = oil and grease TSS 0 300 600 1 3 5 7 0.00 0.03 0.00 0.15 0 30000 0 1500 0 400 0.88 COD 0.66 0.76 TP 0 4 1 5 0.53 0.53 0.78 TN -0.18 - 0 . 0 4 3 -0.14 - 0 . 0 7 2 pH 7.0 8.5 0.00 0.86 0.8 0.69 0.54 -0.18 Cu 0.9 0.85 0.65 0.44 -0.22 0.84 Pb 0.000 0.00 0.25 0.9 0.90 0.64 0.40 - 0 . 0 4 9 0.9 0.9 Zn 0.78 0.79 0.43 0.10 -0.11 0.77 0.82 0.88 OG 0 15 0 1000 0 50000 -0.13 -0.38 0 2 4 6 -0.47 -0.31 7.0 8.0 - 0 . 0 3 3 -0.35 0.000 0.015 -0.23 -0.29 0 10 20 -0.42 Flow