Grey and Bruce Counties Groundwater Study Final Report July 2003 Prepared by: Waterloo Hydrogeologic, Inc. WHI Project # 3020337 Prepared for: County of Bruce County of Grey Ontario Ministry of the Environment Waterloo Hydrogeologic, Inc. 460 Phillip Street – Suite 101 Waterloo, Ontario, Canada, N2L 5J2 Phone: (519) 746-1798 Fax: (519) 885-5262 Email [email protected] Web www.waterloohydrogeologic.com August 5, 2003 Grey and Bruce Counties Groundwater Study Steering Committee Re: Final Report Grey and Bruce Counties Groundwater Study Dear Committee Members, On behalf of our Consultant Team, it is with pleasure that we submit the Final Report for the Grey and Bruce Counties Groundwater Study. The report presents the characterization of regional groundwater resources, and the results of a contaminant sources inventory, groundwater use assessment and the Wellhead Protection Area modeling. Comprehensive data has been compiled, analysed and presented to highlight the significance of this information as it relates to the Objectives of the Groundwater Study. Assimilating the results of such diverse and thorough analyses into a comprehensive report that outlines regional groundwater resource management and local groundwater protection measures has been a challenging but valuable undertaking. The groundwater protection measures will help municipalities develop plans to more adequately manage their groundwater resources. We look forward to your comments on the methodology, analyses and results of this study. Yours truly, WATERLOO HYDROGEOLOGIC, INC. D.J. Miln Harvey, Ph.D., P.Eng. Project Manager Ph: (519) 746-1798, ext. 233 [email protected] Executive Summary Executive Summary Grey and Bruce Counties rely heavily on groundwater as a source of supply for its drinking water needs, and are fortunate that the quantity of groundwater available is capable of meeting the current water demand and that the water is of excellent quality. However, potential threats to the quantity and quality of this resource exist within the Counties. The Grey and Bruce Counties Groundwater Study was undertaken to develop an improved understanding of local groundwater conditions within the context of larger regional groundwater flow systems. This groundwater study has brought together and evaluated an extensive compilation of regional and local water resources information, which is reflected in the scope of work that has been completed. The area encompassed by the study, as presented in Figure 1.1, includes the County of Grey, the County of Bruce, and a 5 kilometer buffer area around them. The study partners acknowledge that the basic groundwater functions (recharging, transmitting, assimilating potential contaminants, storing and discharging water) play an essential role in maintaining the health of an ecosystem. Better understanding these regional groundwater functions is helpful to provide a secure supply of clean water to municipal and communal water systems, as well as to individual groundwater users who do not have access to a municipal supply. Existing and future land use practices exercised throughout the Counties may pose threats to the long-term sustainability of groundwater resources for both quantity and quality. This study provides a more thorough understanding of local and regional groundwater resources that will aid in the development of sound groundwater management and groundwater protection measures to help ensure the long-term sustainability of the resource. The study partners reflect the regional and local relevance of groundwater in this study. They include the Ministry of the Environment (MOE), County governments, Conservation Authorities, and local consultants. The MOE is the project’s major funding organization and provincial partner. The Grey County Planning Department, the Bruce County Planning Department, the Saugeen Valley Conservation Authority (SVCA) and the Grey Sauble Conservation Authority (GSCA) are also major partners to the study and have provided funding for its completion. At the onset of the study and number of objectives were developed by the Study Partners. The objectives of the Grey and Bruce Counties Groundwater Study are provided below: Objective 1: To define and map local and regional groundwater conditions; Objective 2: To define groundwater intrinsic susceptibility; Objective 3: To compile a contaminant sources inventory; Objective 4: To complete wellhead protection area (WHPA) mapping for 48 municipal groundwater well systems; Objective 5: To conduct a contaminant source assessment within each WHPA; Objective 6: To develop a municipal action plan for implementing a groundwater protection strategy; and, Objective 7: To promote public groundwater awareness throughout the study area through open houses, local media news releases, and a project website. Source protection is an excellent term to describe the different study objectives listed above. Source protection is the first of five barriers commonly applied to provide safe drinking water, as outlined in Report 2 of the Walkerton Inquiry (O’Connor, 2002). The other four barriers include i Executive Summary treatment, a secure distribution system, water quality monitoring, and well-planned responses to adverse conditions. It is important to reflect on the detail incorporated into the regional mapping presented in this report and to consider appropriate uses for this information. A large portion of the groundwater and aquifer characterization mapping developed for this study was completed at a regional- scale. The mapping used point information to develop themes such as the depth to bedrock, sand and gravel thickness, water table elevation, and aquifer vulnerability. The point information used to develop this mapping is included as small dots on each relevant map. This has been done to remind the end users of these products that, although the mapping represents continuous surfaces, it was developed from point data that is not evenly distributed throughout the study area. The quality of the point data used in the mapping has been evaluated and is considered acceptable for its purpose, however it has not been field verified. As such, it is important to remember that the mapping is an interpreted representation of the real world. The regional maps are presented at a scale of 1:650,000. This means that a 1 mm line is accurate to within 650 m, and a 1 cm by 1cm square is accurate to within 4.225 ha. This level of detail is not appropriate for site-specific interpretation, but it does provide valuable information for regional scale analyses. This report was organized in sections to address the study objectives outlined above. The sections are organized by topic to coincide with the different regional and local study objectives. The study also includes a comprehensive groundwater protection strategy and provides detailed conclusions and recommendations. Brief descriptions of the topics included in each of the sections are provided in the following paragraph. Section 2 presents the regional groundwater and aquifer characterization. This characterization was used to complete the groundwater susceptibility analysis, which is presented in Section 3. Section 4 presents the groundwater use assessment, which was completed to evaluate how groundwater is used throughout the Counties, and to develop a general regional water budget. A contaminant sources inventory was completed to identify potential contaminant sources throughout the Counties, and is presented in Section 5. Using the information generated in Sections 2, 3, and 4, groundwater modeling was completed to map, at a local-scale, time-of- travel municipal wellhead protection areas. The groundwater modeling and wellhead protection area mapping results are presented in Section 6. In Section 7, the WHPA boundaries are overlain with the groundwater susceptibility and potential contaminant sources and evaluated at a local-scale. Public consultation aspects of the study are presented in Section 8. A groundwater protection strategy is outlined in Section 9. Study recommendations are presented in Section 10. A glossary of technical terms and abbreviations is presented in Section 11, and references are presented in Section 12. Most of the figures for the study are presented in 11”x17” or 30”x36” format under separate cover so that these figures can be reviewed while reading through the report. Groundwater and Aquifer Characterization Groundwater is a safer and cleaner form of water supply, when compared to surface water. Understanding how groundwater moves through the Counties, and the factors that control this movement will help to manage the resource. Information from many different data sources, including the Ministry of Environment, Ministry of Natural Resources, Ministry of Northern Development and Mines, Geologic Survey of Canada, Water Survey Canada, Grey and Bruce Counties, the Saugeen Valley Conservation Authority, ii Executive Summary the Grey Sauble Conservation Authority, local municipalities and local consultants has been incorporated into a project database and GIS. The quality of the different sources of information was evaluated and data that was deemed inaccurate was not included in subsequent analyses. In addition to the information referred to above, the project team compiled a volume of previous reports related to groundwater resources in Grey and Bruce Counties. These reports include local- scale hydrogeologic analyses (completed in support of the development of municipal groundwater supply wells,