SURFACE WATER QUALITY MONITORING

Transcription

1 SFU Facilities Management Services SURFACE WATER QUALITY MONITORING June 1, 2008 to May 31, 2009 Final Draft Report June 30, 2009

2 SIMON FRASER UNIVERSITY FACILITIES SERVICES Surface Water Quality Monitoring June 1, 2008 to May 31, 2009 Submitted to: Frank DeVita Buildings & Grounds Supervisor SFU Facilities Services Burnaby, B.C. By: White Rock, B.C. June 2009

3 Results EXECUTIVE SUMMARY This report discusses surface water quality information of the SFU enclave area that was monitored from June 2008 to May The rationale for the monitoring program was to provide background data and a better understanding about the excessively high conductivity values that had been observed in the last five years in some of SFU s surface drainage. A strong correlation was found between specific conductivity and dissolved chloride originating from road salt. Specific conductivity therefore served as a good proxy variable for dissolved chloride. For the purpose of this monitoring program, and as a practical application, the BC Approved Water Quality Guidelines for chloride were transposed to a mean (sub-lethal) and maximum (lethal) conductivity criterion of 551µS and 2045µS respectively. Surface water conductivity was greatest at monitoring sites close to road salt sources such as SFU s salt storage facility and parking lots. At these locations, the average annual conductivity exceeded the maximum criterion for the protection of freshwater aquatic life. Two major storm water discharge points to Stoney Creek watershed had an average annual conductivity value that exceeds the mean criterion for the protection of aquatic life. The control site that discharges to Silver Creek had an average annual conductivity level that was below the mean criterion for the protection of aquatic life. After the application of road salt, monitoring sites (with the exception of the control site) generally showed a sharp increase in conductivity well above the lethal level for the protection of aquatic life. After the application of road salt ceased, conductivity levels remained excessively high during much of the spring and summer primarily due to the influence of salt contaminated groundwater. During this period conductivity declined only when surface water was diluted with rain water during storm events. The lowest declines in conductivity were evident during the wettest months of October, November, and December. Some preliminary recommendations are made on how these salt contamination issues should be addressed further. Page 1 of 35

4 TABLE OF CONTENTS Executive Summary... 1 Table of Contents... 1 List of Figures, Tables, and Appendices Introduction Goals and Objectives Study Area and Procedures Results and Discussion Sampling Sites Local Weather and Salt Usage Water Quality Guidelines Specific Conductivity Spatial Pattern of Conductivity Temporal Variations in Conductivity Runoff from Snow Storage Sites Cyanide Toxic Metals Fecal Coliforms Conclusions Recommendations Appendices...32 Page 2 of 35

5 LIST OF FIGURES, TABLES, AND APPENDICES Figure 1. Location of water quality monitoring sites. Figure 2a. Monthly total rainfall (mm),. Figure 2b. Winter air temperature from Dec. 1, 2008 to March 31, Figure 3. Major cations and anions in Salt Creek. Figure 4. Conductivity chloride regression for SFU sites. Figure 5. Average annual conductivity values at different monitoring sites. Figure 6. Conductivity and rainfall at MA1. Figure 7a Conductivities at SC2 (control) Figure 7b Conductivities at MH8F Figure 7c Conductivities at SCr Figure 7d Conductivities at Lot Be Figure 7e Conductivities at Lot Bw Figure 7f Conductivities at Lot C Figure 8. Non-compliance of metal results. Table 1. Summary of fecal coliform results. Appendix 1. Specific conductivity measurements. Appendix 2. Analytical laboratory results. Page 3 of 35

6 1.0 INTRODUCTION The Official Community Plan for SFU states that pre-development water quality is to be maintained to ensure that downstream aquatic life is not adversely affected. This principle is also enunciated in the SFU Strategic Infrastructure Plan 1. The principle of maintaining or exceeding water quality objectives is also reflected in the Burnaby Mountain Watercourse & Stormwater Management Plan 2, which was approved in 2002 by all levels of government as a condition for the development of the UniverCity community at SFU. The main rationale for these planning principles is to protect the water quality integrity of Burnaby Mountain s headwater drainages that lead to sensitive fish bearing water in the Stoney Creek, Silver Creek, and West Eagle Creek drainage areas. The majority of SFU s stormwater drainage discharges into the Stoney Creek drainage area. Stoney Creek supports spawning populations of Chum, Coho, and Steelhead salmon, along with Cutthroat and Rainbow trout. In the past decade, Stoney Creek has been the subject of considerable environmental restoration and enhancement efforts by the Stoney Creek Environment Committee (SCEC). Over approximately the last five years, water quality monitoring by the SCEC has revealed periodically high levels of specific conductivity in various tributaries of Stoney Creek 3. Similar results of excessively high conductivity in SFU s surface water drainage have also been documented since 2003 in the UniverCity s environmental monitoring reports 4. In 2008, SFU s Facilities Services decided to collaborate with interested parties monitoring SFU s water quality, so that the cause of these high conductivity levels could be determined, and measures developed to mitigate this water quality impact. Although the focus of the monitoring program was on conductivity and chloride, total metals and coliform bacteria were included as a value added benefit. This report provides initial data results of the SFU Facilties Services water quality monitoring program for EarthTech SFU Strategic Infrastructure Plan. Report prepared for SFU Campus Planning and Development. 2 CH2M-Hill Burnaby Mountain Watercourse & Stormwater Management Plan. Report prepared for the Burnaby Mountain Community Corp. 3 Pers. Comm. Jennifer Atchison and Vladimir Soukhatchev, SCEC 4 Kistritz Consultants Ltd., , Interim Environmental Monitoring Reports, No. 2 to 12, Reports prepared for SFU Community Trust. Page 4 of 35

7 2.0 GOALS AND OBJECTIVES The goal of the monitoring program was to obtain water quality baseline information at selected sites for These monitoring results therefore represent a point of reference to which future comparisons can be made for the determination of the effects of best management practices on surface water quality. The monitoring work had the following objectives: Water quality information will be obtained for major storm water point source discharges from the University enclave area to the Stoney Creek drainage area. Water quality information will be obtained from stations that are close to major salt contamination sources. Sites will be monitored on a monthly to semi-monthly basis to obtain a seasonal overview of existing water quality conditions. Water quality monitoring results will be used to characterize baseline conditions of critical parameters such as conductivity, chloride, metals, cyanide, and coliform bacteria. Preliminary recommendations will be made on these critical water quality issues and concerns to assist and enhance SFU s salt management planning. Page 5 of 35

8 3.0 STUDY AREA AND PROCEDURES The study area for the water quality monitoring work is the Simon Fraser University enclave, which is the campus area bounded by University Drive (see figure below). A total of seven sites were selected for water quality monitoring (Figure 1). Two of these (MA1 and MH8F) were major point discharges from the University enclave area into Stoney Creek watershed. A point discharge (SCr) close to the salt storage shed was monitored since it is known to have excessively high conductivity levels. Three additional point discharges associated with parking lots B and C were also monitored because large paved areas contribute significant amounts of pollutants and salt to storm water runoff. A control site (SC2) was selected for comparative purposes. Page 6 of 35

9 From June 2008 to May 2009, the sites were monitored monthly during rain events and weekly during freezing weather when salt was applied to roads and parking lots. Monitoring included field measurements of temperature, turbidity, ph, and specific conductivity. Bottled samples were taken for the remaining water quality parameter, which were submitted to Cantest for laboratory analysis. Specific conductivity was measured with an Oakton EC Tester with a range of 0 to 2000 µs ±1% full-scale. Conductivities >2000 were measured using a Pinpoint meter, which had a maximum reading of 20,000 µs ±2%. Any conductivity values >20,000 were submitted to Cantest for laboratory testing. Meteorological data including air temperature and rain was obtained from a local weather station situated at the Cornerstone building, 8960 University High Street. Page 7 of 35

10 Figure 1. Location of water quality monitoring sites, salt storage area, and drainage areas (yellow) discharging into Stony Creek watershed. Lot C Lot Be Lot Bw Salt Storage MH8F SCr. MA1 SC2 Page 8 of 35

11 4.0 RESULTS AND DISCUSSION 4.1 Sampling Sites The two large yellow areas in Figure 1 roughly delineate the University enclave areas that discharge into Stoney Creek watershed. Most of the east enclave area discharges into a headwater stream of Stoney Creek named tributary 3A where monitoring site MA1 is located. This site was monitored at the open natural channel as it enters the culvert crossing of University Drive. Monitoring station MH8F is located at the Gaglardi Way storm interceptor that receives the discharge from the north and west enclave area. This site was accessed at a manhole. Drainage from B parking lots east (Be) and west (Bw) were sampled at their main storm water outfalls. Parking lot C was monitored at a manhole. Monitoring site SCr is the so-called Salt Creek that receives runoff from the Facilities Services works yard and salt storage area. This site was monitored at an outfall. Site SC2 is considered to be a control site since it has a small developed area along with mostly forested land that receives relatively low amounts of road salt. This site was monitored at the open natural channel as it enters the culvert crossing of University Drive. Page 9 of 35

12 Metric Tonnes Local Weather and Salt Usage The local weather on Burnaby Mountain is a significant factor affecting water quality parameters such as conductivity, dissolved chloride, and other water quality parameters. This is due to the application of road salt during freezing temperatures. During heavy rainfall events, water quality is also affected by the amount of storm water discharged into natural drainage areas. Another important weather factor is the interceding period between rain storms, during which substantial amounts of pollutants accumulate on paved surfaces. This accumulated pollution load is then flushed into drainages upon the next large rain event. Figure 2a and 2b provide a summary of local rainfall and temperature conditions in the study area during the monitoring period. As shown in Figure 2a, June through to September 2008 was generally dry with the exception of some unusual rainstorm activity in the latter part of August. The total amount of rain increased in October to November The first major snow storm of the winter period occurred on December 12, 2008, after which cold weather persisted to the end of March 2009 (Figure 2b). Most significant however, was the total accumulated snowfall in December 2008 (162.2 cm), which was more than double the worst year of the past five years of SFU snowfall records. A total of 1042 tons Total Annual Salt Usage at SFU of bulk salt plus 30,000 litres of liquid brine were used during the winter of Salt usage has varied over the past six years (see figure); however, it is difficult to attribute this variation to any specific factor (such as snowfall). The annual amount of salt 0 usage depends on 2003/ / / / / /09 the type of snow Winter storm (prolonged or intermittent), frequency of black ice conditions, as well as subjective factors judged by the application operator (pers.comm F. DeVita) Page 10 of 35

13 Figure 2a. Monthly Total Rainfall (mm) June 2008 to May Rainfall (mm) June July August September October November December January February March April May Page 11 of 35

14 SFU Surface Water Quality Monitoring Winter Air Temperatures from Dec. 1, 2008 to March 31, 2009 Page 12 of 35 December 1, 2008 Degrees Celsius December 3, 2008 December 6, 2008 December 9, 2008 December 12, 2008 December 15, 2008 December 18, 2008 December 21, 2008 December 24, 2008 December 27, 2008 December 30, 2008 January 2, 2009 January 5, 2009 January 8, 2009 January 11, 2009 January 14, 2009 January 17, 2009 January 20, 2009 January 23, 2009 January 26, 2009 January 29, 2009 January 31, 2009 February 3, 2009 February 6, 2009 February 9, 2009 February 12, 2009 February 15, 2009 February 18, 2009 February 21, 2009 February 24, 2009 February 27, 2009 March 2, 2009 March 5, 2009 March 8, 2009 March 11, 2009 March 14, 2009 March 17, 2009 March 20, 2009 Figure 2b.

15 4.3 Water Quality Guidelines Water quality guidelines for the protection of freshwater aquatic life are set by federal (CCREM 5 ) and provincial (MOE 6 ) government regulatory authorities. Regulated water quality parameters relevant to this monitoring program include ions of chloride and cyanide, and the total metals aluminum, arsenic, cadmium, chromium, copper, iron, lead, mercury, and zinc. Chloride Dissolved chloride is a regulated water quality parameter due to its toxicity to aquatic life, and its presence in surface and ground water when road salt is used as a deicing agent. The recommended water quality guideline for chloride is as follows. 600 mg/l for maximum concentration 7, and 150 mg/l for 30-d average 8 concentrations. The BC Ministry of Environment states that: The application of road salt for winter accident prevention is an important source of chloride to the environment, which is increasing over time due to the expansion of road networks and increased vehicle traffic. Road salt (most often sodium chloride) readily dissolves and enters aquatic environments in ionic forms. Although chloride can originate from natural sources, most of the chloride that enters the environment is associated with the storage and application of road salt. As such, chloride-containing compounds commonly enter surface water, soil, and ground water during snowmelt. Chloride ions are conservative, which means that they are not degraded in the environment and tend to remain in solution, once dissolved. Chloride ions that enter ground water can ultimately be expected to reach surface water and, therefore, influence aquatic environments and humans. Among the species tested, freshwater aquatic plants and freshwater invertebrates tend to be the most sensitive to chloride. Recently, the Canadian government classified road salt as toxic under the Canadian Environmental Protection Act (1999). Although there are no specific water quality guidelines for conductivity, the significance of this water quality parameter is discussed in section 4.4 of the report. 5 Canadian Council of Resource and Environment Ministers 6 B.C. Ministry of Environment, Environmental Protection Division 7 Instantaneous maximums 8 Average of five weekly measurements taken over 30-day period Page 13 of 35

16 Cyanide Cyanide (usually in the form of sodium hexacyanoferrate) is often added to road salt as an anti-caking agent. This toxic element can therefore show up in surface and groundwater in areas where road salt is applied. Cyanide in its weak-acid dissociable form is lethal to aquatic life at concentrations greater than 10 µg/l, and sub-lethal at concentrations above 5 µg/l. 9 The measure of total cyanide in surface water is therefore a conservative estimate of the degree of toxicity. Metals Environmentally regulated toxic metals typically occur in undetectable to trace amounts in natural, undeveloped watersheds. There are a few metals such as aluminum, iron, and arsenic that can occur naturally at concentrations above water quality guidelines for the protection of aquatic life. However, toxic metals concentrations that are above water quality guidelines are most often found in urban watersheds. This is due to the variety of waste products associated with human activities. Vehicle traffic is a large source of toxic metals in the urban environment. Toxic metals that accumulate on paved surfaces are flushed into watercourses during the initial stage of rain storms. Because of their strong affinity to fine sediments and organic matter, metals also tend to settle and accumulate in stream sediments. Toxic metals have lethal and sub-lethal water quality guidelines that will vary with the amount of water hardness. Metals such as cadmium, lead, nickel, and silver are less toxic in harder water, whereas copper is less toxic in softer water. Therefore, specific water quality guidelines for metals depend on water hardness. Fecal Coliform Bacteria Although not regulated for the protection of freshwater aquatic life, fecal coliform bacteria are of interest when they shown up consistently and in high amounts in surface water, as this may be an indication of sewage contamination. 9 B.C. Ministry of Environment, Environmental Protection Division. Page 14 of 35

17 4.4 Specific Conductivity Specific conductivity is a practical water quality parameter used to measure the water s ionic activity and content. As the concentration of ionic (dissolved) constituents increases, so too does the specific conductivity. Conductivity values typically average below 100 µs for most natural headwater streams. Average values between 100 to 300 µs are associated with rivers or higher order streams located near the bottom of a watershed. Normal conductivity levels from 300 up to one thousand or more will occur in natural streams such as hot springs where there is a high minerals source. Seawater is typically in the 30,000 to 40,000 range. In freshwater, elements whose ionic forms contribute most to conductivity include: calcium (Ca 2+ ), magnesium (Mg 2+ ), sodium (Na + ), potassium (K + ), bicarbonate (HCO 3- ), sulfate (SO 4 2- ), and chloride (Cl - ). Sodium and chloride ions are of particular interest to this study as they are the chemical elements that make up road salt (NaCl). Conductivity is very responsive to the concentration of dissolved chloride. High conductivity levels measured in Salt Creek (SCr) located below the salt storage area are corroborated by an overwhelming dominance of Na and Cl ions (Figure 3). The strong relationship between conductivity and chloride is also evident when concurrent water quality measurements are analyzed in a data regression. Figure 4 shows the strong relationship of the data acquired during this monitoring program. Therefore, specific conductivity proved to be a good proxy variable for predicting the level of dissolved chloride. Similar conclusions have also been made by other researchers. 10 Using the linear equation, y = x where y = dissolved chloride in mg/l, and x = conductivity in µs, the dissolved chloride guidelines for the protection of aquatic life can thus be interpolated to conductivity guidelines, as follows: 2045 µs maximum limit 551 µs 3-d average limit 10 Mooney, R.J. et.al Verifying the use of specific conductance as a surrogate for chloride in seawater matrices. Report by In-Situ Inc. Page 15 of 35

18 Figure 3. Major Cations in Salt Creek Conductivity = 2900 µs on June 10, 2008 Ca 14% Mg 5% K 3% Na 78% HCO3 8% NO3 Major Anions in Salt Creek 1% Conductivity = 2900 µs on June 10, 2008 SO4 3% Cl 88% Page 16 of 35

19 Figure 4. Conductivity Chloride regression for SFU sites monitored from June 2008 to March Dissolved Chloride, mg/l y = x R 2 = Specific Conductivity, µs Page 17 of 35

20 4.5 Spatial Pattern of Conductivity Average annual conductivity levels varied significantly between the various monitoring sites. Not surprisingly, conductivity levels were greatest at monitoring sites close to road salt sources such as the salt storage facility (SCr), and parking lots (Lot C, Lot Be, Lot Bw). Annual average conductivity was lower at the two major discharge points (MA1, MH8F) of the enclave area, and lowest at the control site (SC2). The spatial pattern of conductivity for the monitoring sites can thus be sorted into three important groups with respect to average annual water quality compliance. 1. Conductivites > lethal limit: Monitoring sites closest to road salt sources such as the salt storage site (SCr) and parking lot Bw had an annual average conductivity level that was above the lethal limit of 2045 µs. Parking lots (Lot C and Be) are also included in this group because the average conductivity approached lethal level. These four sites are shown as red bars in Figure Conductivities > sub-lethal limit: Average annual conductivity at the two locations where the University enclave discharges into Stoney Creek (MH8F and MA1) was above the sub-lethal limit of 551 µs. These two sites are shown as cautionary orange bars in Figure Conductivities < sub-lethal limit: Average annual conductivity at the control site (SC2) was below the sub-lethal limit (shown as a green bar in Figure 5). Page 18 of 35

21 Figure 5. Average annual conductivity values at different monitoring sites Average Annual Conductivity (± Standard Error) June 2008 to May Conductivity µs Lethal Limit Sub-Lethal Limit 0 SC2 MH8F MA1 Lot Be Lot C SCr Lot Bw Monitoring Site Page 19 of 35

22 4.6 Temporal Variations in Conductivity The temporal variation in conductivity was measured on a weekly to monthly time scale. On that basis, large seasonal changes in conductivity were evident at all of the monitoring stations. There was a sharp increase in conductivity shortly after the first application of road salt in winter, followed by a very slow decline in conductivity over the remaining seasons of spring, summer and fall. During the summer, there was no discharge from the parking lots, except during rain events. Variations in conductivity during the declining phase were due to changing amounts of groundwater or rainwater present in the surface drainage. The conductivity in surface drainage was higher during dry periods when groundwater dominated, and lower during wet periods when rainwater was dominant. On the basis of our analyses, we found that groundwater conductivity was positively related to the amount of dissolved chloride (see Figure 4). Therefore, groundwater has a significant influence on the level of conductivity (chloride) present in the surface water at SFU. On the basis of these observations, the three environmental factors that seem to have a strong influence on temporal variations in water conductivity can be summarized as follows. 1. Groundwater: High conductivity values were evident during dry periods of the spring and early summer when relatively large contributions of groundwater entered the surface water. 2. Rain: During wet periods, and especially in October and November (see Figure 2a), conductivities were lower due to the substantial dilution of groundwater with the much softer rain water. 3. Ice: With the onset of freezing conditions starting on December 12, 2008 (see Figure 2b), conductivity levels were especially high due to the application of road salt. The application of road salt continued periodically until the first week of April Figure 6 shows the sharp increases in conductivity at monitoring station MA1 during the period of road salt application (December to April). During the spring and summer conductivity periodically declined during rain events. This decline in conductivity became most pronounced during the rainy season in October, November, and December. Similar seasonal patterns of conductivity were observed at all other monitoring stations (Figure 7 a to f). Page 20 of 35

23 Figure 6. Conductivity at MA1 shown in bottom bars, with rainfall shown in top bars Conductivity (µs) Rain (mm) Conductivity at MA1 SFU Rainfall Application of Road Salt June 1, 2008 July 1, 2008 August 1, 2008 September 1, 2008 October 1, 2008 November 1, 2008 December 1, 2008 January 1, 2009 February 1, 2009 March 1, 2009 April 1, 2009 May 1, 2009 Page 21 of 35

24 Figure 7. a & b SC2 (Control) Dashed line indicates lethal and sub-lethal level Specific Conductivity µs June 1, 2008 July 1, 2008 August 1, 2008 September 1, 2008 October 1, 2008 November 1, 2008 December 1, 2008 January 1, 2009 February 1, 2009 March 1, 2009 April 1, 2009 May 1, 2009 MH8F Dashed line indicates lethal and sub-lethal level Conductivity µs June 1, 2008 July 1, 2008 August 1, 2008 September 1, 2008 October 1, 2008 November 1, 2008 December 1, 2008 January 1, 2009 February 1, 2009 March 1, 2009 April 1, 2009 May 1, 2009 Page 22 of 35

25 Figure 7. c & d 5000 SCr Dashed line indicates lethal and sub-lethal level Conductivity µs June 1, 2008 July 1, 2008 August 1, 2008 September 1, 2008 October 1, 2008 November 1, 2008 December 1, 2008 January 1, 2009 February 1, 2009 March 1, 2009 April 1, 2009 May 1, Lot Be Dashed line indicates lethal and sub-lethal level Conductivity µs June 1, 2008 July 1, 2008 August 1, 2008 September 1, 2008 October 1, 2008 November 1, 2008 December 1, 2008 January 1, 2009 February 1, 2009 March 1, 2009 April 1, 2009 May 1, 2009 Page 23 of 35

26 Figure 7. e & f 5000 Lot Bw Dashed line indicates lethal and sub-lethal level Conductivity µs June 1, 2008 July 1, 2008 August 1, 2008 September 1, 2008 October 1, 2008 November 1, 2008 December 1, 2008 January 1, 2009 February 1, 2009 March 1, 2009 April 1, 2009 May 1, Lot C Dashed line indicates lethal and sub-lethal level Conductivity µs June 1, 2008 July 1, 2008 August 1, 2008 September 1, 2008 October 1, 2008 November 1, 2008 December 1, 2008 January 1, 2009 February 1, 2009 March 1, 2009 April 1, 2009 May 1, 2009 Page 24 of 35

27 4.7 Runoff from Snow Storage Sites Plowed snow was dumped into large piles in parking lots C and B. Consequently, some concern has been expressed about the quality of the melt water from these snow piles with respect to salt contamination. Conductivity measurements of snow melt water were taken at Lot C on April 7, 2009, and Lot B and the HIghstreet Lot on April 8, All of the snow melt water had conductivity values that ranged between 10 µs and 20 µs, indicating extremely soft water that would be almost devoid of any chloride. Photo 1. Snow melt water entering catch basin in Lot C. Page 25 of 35

28 4.8 Cyanide Total cyanide was not detectable in water sampled at all monitoring sites on December 29, 2008, January 6, 2009, and February 25, On December 29, 2008 total cyanide was tested in bulk and bagged salt, and brine used for SFU s deicing operations. The salt samples did not contain any detectable traces of cyanide. However, brine contained 60 µg/l of cyanide. Detectable concentrations of cyanide have been noted by the Stoney Creek Environment Committee during their environmental monitoring of the Stoney Creek headwaters (pers. Comm. Vladimir Soukhatchev). The inconsistent and periodic presence of cyanide in surface water suggests that this chemical element may occur in unpredictable amounts in the bulk and bagged salt used by SFU. Page 26 of 35

29 4.9 Toxic Metals Laboratory results for total metal concentrations in surface water were analyzed to determine compliance with provincial water quality guidelines for the protection of freshwater aquatic life 11. Data results are provided in Appendix 1, where noncompliance with water quality criteria is indicated in bold and highlighted in yellow. Of the 53 water samples tested from five different monitoring stations, 32% to 85% of the test results were non-compliant for copper, aluminum, iron, and chromium. Non-compliance for lead, zinc, selenium, mercury, cadmium, and molybdenum ranged from 2% to 13%. Arsenic, nickel, and silver were below detection or in compliance for all of the tests. Figure 8 shows the degree of noncompliance for various toxic metals monitored. Figure 8. Non-compliance of metal results with provincial water quality criteria as a percentage of all samples tested during the monitoring period. 90% 80% 70% Percent Non-Compliance 60% 50% 40% 30% 20% 10% 0% Copper Aluminum Iron Chromium Lead Zinc Selenium Mercury Cadmium Molybdenum Aresnic Nickel Silver Metal 11 B.C. Ministry of Environment, Environmental Protection Division, Water Quality Criteria Page 27 of 35

30 It should be noted that the occurrence of high (and non-compliant) metal concentrations in urban storm water have been well documented throughout North America. These storm water contaminants largely originate from materials that accumulate on paved surfaces, and are flushed into storm drains during rainfall events. Many of these toxic metals are usually attributable to vehicle exhaust emissions, break dust, fuel and oil drippings, etc. found in high concentrations along major transportation routes and parking lots. Cadmium, copper, chromium, lead, mercury, and zinc periodically showed up in high concentrations that exceed water quality criteria. However, the metals tested during this monitoring program were well within the range of storm water values measured at comparable sites such as the University of British Columbia. 12 There may also be natural metal sources. For example, aluminum and iron, which had a high rate of non-compliance, are among the most abundant elements in the earth s crust. High concentrations of these metals are typical for water that contains a relatively high amount of inorganic particulate suspended matter, such as storm water. It is assumed that the toxic dissolved form of aluminum comprised only a small percentage of the total concentration of aluminum; although this should be confirmed in future monitoring efforts. 12 Raincoast Applied Ecology University of British Columbia Stormwater Monitoring Program. August 2001 to September 2002 Summary. Rept. prep. for UBC Utilities. Koch, F.A., and K.J. Hall Survey of Wastewater Quality in the Sewerage System of the University of British Columbia. Westwater Research Centre, Tech. Rept. No. 24. Page 28 of 35

31 5.0 Fecal Coliforms Fecal coliform values varied considerably between the monitoring stations and over the period of sampling. Values ranged from non-detectable to 4,300 colonies per 100 ml. The highest median and maximum values were associated with the largest storm water catchment area (MH8F) and the summer period (Table 1), which is typical for urban storm water runoff. Fecal coliforms did not consistently show up in high numbers at any of the monitored stations, and as such it is inferred that there were no sewage contamination sources present. Table 1. Summary of fecal coliform results. Lot C Lot Bw MH8F SCr. MA1 03-Jun Jul Aug Oct Oct Nov Dec Dec Feb Mar May < 1 29 Median Maximum Minimum Page 29 of 35

32 5.0 Conclusions Because of the strong relationship between chloride concentration and specific conductivity, a linear regression was used to interpolate a lethal and sub-lethal conductivity water quality guideline of 2045 µs and 551 µs respectively. Specific conductivity therefore proved to be a practical proxy variable for chloride. Storm water discharges from below parking lots B and C, and the salt storage facility had average annual specific conductivities that were near and above levels lethal to freshwater aquatic life. Average annual conductivity was sub-lethal to aquatic life at the two monitoring locations where storm water enters the ambient environment. There was a sharp increase in conductivity shortly after the first application of road salt in winter, followed by a slow decline in conductivity over the remaining seasons of spring, summer and fall. High conductivity levels persisted in groundwater for many months after the winter season when the last application of road salt took place. Salt contaminated groundwater was monitored not only below the salt storage facility, but also at the parking lot discharges, suggesting that salt contaminated soil and groundwater may exist along most major traffic routes, pedestrian walkways, and parking lots. Melt water from snow storage areas proved to free of any salt contamination. Total cyanide was not detected in surface water during this monitoring period. However, cyanide was found in the brine solution stored next to the salt shed. Total metals that were non-compliant with water quality criteria for the protection of aquatic life for > 30% of the samples included copper, aluminum, iron, and chromium. However, the concentration range of monitored metals was typical for storm water analyzed in other GVRD locations such as UBC campus. Fecal coliforms did not consistently show up in excessively high numbers at any of the monitored stations. Page 30 of 35

33 6.0 Recommendations Specific conductivity should continue to be measured as a proxy variable of dissolved chloride to determine water quality compliance with government regulations. Due to the large and rapid fluctuations of conductivity evident in the surface water, we recommend that a continuous conductivity probe and data logger be used for ongoing monitoring at station MA1. The long range water quality goal for SFUFS should be to strive for average annual conductivity levels that are below the sub-lethal limit for surface water discharging to the ambient environment. The control site (SC2) achieved this average annual level during the water quality monitoring period. Efforts should be initiated to reduce the amount of salt that infiltrates into the ground. A good start would be to identify and fix sites where salt contaminated runoff from paved areas enters the surrounding ground due to missing curbs, cracked pavement, leaky pipes, or any other compromised storm water conveyances. Improved containment of the existing salt storage and handling facility is required to minimize the risk of salt contamination to the surrounding environment. The degree of existing groundwater contamination at the salt storage facility needs to be assessed and a remediation or containment strategy developed to reduce the amount of contaminated groundwater from entering surface drainages. Various alternative salt management practices must be identified and tested in order to reduce the total amount of salt applied to paved surfaces. Research should be initiated to develop feasible options for mitigating the shock loading of salt into surface waters. Shock loading is the first flush event after salt has been applied when the conductivity in surface water increase rapidly from several hundred to several thousand µs. Page 31 of 35

34 Appendix 1. Specific Conductivity Measurements Page 32 of 35

35 Appendix 2. Analytical Laboratory Results Page 33 of 35