WATER QUALITY ASSESSMENT Buckhorn Creek & the Welland River In the Vicinity of the Glanbrook Landfill 2006 For: Fabiano Gondim, P. Eng. Supervisor of Landfills Waste Management Division Public Works Department City of Hamilton 120 King Street West Suite 1170 Hamilton, Ontario L8P 4V2 By: The Niagara Peninsula Conservation Authority March 2007 1.0 INTRODUCTION 1.1 Background The Glanbrook Landfill study site is located in the former Township of Glanbrook in the southeast portion of the City of Hamilton, Ontario. The landfill is currently the only open and operating landfill in the City of Hamilton, and has been in operation since 1980. The Glanbrook Landfill is designed to receive domestic, commercial, and non-hazardous solid industrial waste. Leachate is collected via a leachate collector system and is transported off-site to the City of Hamilton’s Waste Water Treatment Plant. Stormwater drainage is managed using a combination of open ditches and retention ponds. The site is currently operated by Waste Management of Canada Corporation (formerly named Canadian Waste Services Incorporated) on behalf of the City of Hamilton. The City of Hamilton currently has ten surface water quality monitoring stations on the Welland River and Buckhorn Creek, and select surface water samples are taken monthly for condensed parameters and four times a year for more comprehensive testing to determine water quality impacts. Both waterways meander through the landfill property and converge east of the site (Figures 1a, 1b). Annual monitoring reports have stated that there is no chemical evidence of landfill leachate impact on water quality in Buckhorn Creek and the Welland River (Golder Associates Ltd., 2002). In order to establish conclusively how the landfill is affecting aquatic biota, the density and diversity of benthic macroinvertebrates should be assessed in these watercourses. Figure 1a: Regional map of the Glanbrook Landfill study area 2 Figure 1b: Local map of the Glanbrook Landfill study area Five times within the past ten years, the Niagara Peninsula Conservation Authority (NPCA) has conducted water quality assessments using benthic macroinvertebrates as a measure of water quality in the vicinity of the Glanbrook Landfill for the City of Hamilton. The purpose of these assessments was to determine if stormwater runoff and leachate from the landfill were negatively impacting water quality and aquatic biota in the Welland River and Buckhorn Creek. Results from these studies indicate that water quality in these watercourses has improved since 1996, with limited landfill impacts observed in 1996 and no impacts observed in 1998, 2002, and 2004. The purpose of the 2006 water quality assessment is to follow-up on previous NPCA assessments and to determine water quality trends in both Buckhorn Creek and the Welland River in the areas surrounding the Glanbrook Landfill. In addition, this study will identify specific sources that are causing adverse impacts to these watercourses, and provide recommendations for further study. 3 1.2 Biological Monitoring Biological monitoring, or biomonitoring, is the use of living organisms to determine the quality of the aquatic environment. Biomonitoring surveys can be conducted to determine the effects of an activity on the environment, and can also be an effective tool to regularly monitor ecosystem health as it pertains to legally mandated water quality standards. A standardized system of sampling and analyzing water quality on a biological basis has been developed by the Ministry of Municipal Affairs and Housing, Planning and Policy Branch (Griffiths, 1999). This water quality measurement system is an extension of the Biological Monitoring and Assessment Program (BioMAP) developed by Dr. Ron Griffiths. BioMAP is scientifically recognized as a valid water quality monitoring technique. It is a macroinvertebrate based biological monitoring program that provides an effective and simple method to determine the ecological health of an aquatic system. The NPCA has adopted the BioMAP technique in order to assess water quality in the watershed, and has been working closely with Dr. Griffiths since 1995. 2.0 WATER QUALITY 2.1 Measures of Water Quality Water quality monitoring has historically relied heavily upon chemical testing as a means of measuring the quality of water. While there are many benefits to chemical monitoring, it has become widely recognized that there are limitations to monitoring programs based strictly on chemical analysis (US EPA, 1989). Impacts to water quality resulting from non-chemical activities will not be detected. Physical alterations such as habitat destruction, flow alterations and drainage activities are typically immeasurable through chemical monitoring programs. Other problems that limit the usefulness of chemical monitoring include the fact that it is prohibitively expensive to monitor at all times. As a result, spills and other events may go undetected. Furthermore, not all potentially toxic chemicals reach detectable concentrations. Aquatic organisms can be used to directly assess and monitor the water quality of streams. They can also be used to evaluate the effectiveness of environmental policies and planning decisions related to ecosystem health. Although fish are perceived to have more social relevance, benthic macroinvertebrates are the most widely used group of organisms for biological water quality programs. They represent the organisms which fish feed on; thus the two are directly linked. Fish will not exist where there is no food for them to eat. Benthic macroinvertebrates are the larger organisms inhabiting the bottom portion or substrate of waterways for at least part of their cycle. As a general rule, macroinvertebrates include those species whose body width exceeds 500µm (micrometers). The larger species are easily captured and more 4 easily identified, making the analysis cost-effective. Some typical macroinvertebrate species that are commonly found in the Niagara Peninsula include clams, snails, leeches, worms, the larval stages of dragonflies, stoneflies, caddisflies, mayflies, beetles, and a wide variety of other insects. The advantages of using benthic macroinvertebrates as indicators of water quality are well known. They are abundant in all types of aquatic systems, and can be easily collected and identified using relatively inexpensive equipment. Because of their restricted mobility and habitat preferences, macroinvertebrates usually remain in a localized area. As a result, they are continuously subjected to the effects of all pollutants and environmental stream conditions over time and can provide a broad overview of water quality related problems. As a group, benthic macroinvertebrates show a wide range of tolerances to various degrees and types of pollution. The life history of most species ranges from a few months to several years. Sampling benthic macroinvertebrates once or twice a year during the spring and fall, when species are larger and more developed, is sufficient to assess the benthic community on an annual basis. They provide an early warning signal of aquatic degradation resulting from changes in the watershed, and demonstrate water quality improvements in response to pollution abatement and restoration programs. 2.2 Assessment of Water Quality The identification and enumeration of benthic macroinvertebrates provides the foundation for water quality assessment and requires a specialist trained in benthic macroinvertebrate taxonomy. Genus is the basic taxonomic level of identification, however, if organisms within a genus are known to show a wide range of tolerances to different environmental stresses further identification to the species level is required. This level of identification provides for a more standardized method of comparing and relating water quality results. Biological indices are used to translate benthic macroinvertebrate data into a measure of water quality. These indices incorporate information about the ecological requirements of individual macroinvertebrates using a measure of their abundance. Each macroinvertebrate has been assigned a sensitivity value, and all benthic macroinvertebrates collected in a sample will contribute to the calculated Water Quality Index (WQI) designed by Dr. Griffiths (1993). The classification of water quality based on the calculated WQI is outlined in Table 1. Refer to Table 2 for a description of watercourse classification. Water quality is classified as either impaired or unimpaired. Unimpaired water quality is recognized by the occurrence of organisms whose environmental requirements and tolerances match those which would be expected at the site without the input of any stresses. At sites where water quality is impaired, the organisms found are less sensitive and are therefore more tolerant to environmental stresses than organisms which would have historically occurred. The benthic population at an impaired site would typically be dominated by these more tolerant species, and as a result biodiversity at the site would be 5 quite low. In order to aid in the interpretation of water quality indices and for comparative purposes, benthic communities should be sampled throughout the watershed in order to represent a variety of different water quality conditions (i.e. good verses poor). Table 1: Classification of water quality based on values from the BioMAP Water Quality Index (WQI) Threshold values to classify the water quality of watercourses based on BioMAP (d) and BioMAP (q) water quality