| Abstract/Description or Keywords |
The unconfined sand and gravel aquifer at Grand Forks, located in the southern interior of British Columbia is one of the most important aquifers in British Columbia; the aquifer has been classified by the Ministry of Environment as an “IA”, heavily developed, highly vulnerable to contamination, aquifer. Studies have been conducted on the aquifer to address specific groundwater issues since the 1960’s and initially focussed on developing community well water supplies. In the late 1980-1990’s, additional studies were done to assess the extent of nitrate contamination. Since the late 1990’s, the Ministry of Environment and Simon Fraser University have jointly focussed efforts in characterizing the aquifer to support the local community in groundwater protection. This report summarizes the state of understanding of the groundwater characteristics of the Grand Forks Aquifer - its architecture, geology, the aquifer’s thickness, potential yield, water chemistry, intrinsic vulnerability, and capture zone areas for community wells. The report also presents characteristics of the aquifer that are more dynamic, based on Simon Fraser University’s finite-difference numerical model - the direction of groundwater flow, under non-pumping conditions as well as under pumping condition, the time of travel of water (for any non-reactive contaminants dissolved in the water) to reach pumping community wells, and the hydraulic relationship between the aquifer and Kettle River. The information has potential application to assist the local community in addressing potential risks to their groundwater, and also to enable them to consider groundwater sustainability and protection in land use decision-making and planning for growth. This report provides a number of recommendations that would strengthen the current management and protection of this provincially important aquifer: _ The affects of proposed pumping of any new large capacity water supply well (e.g., >3,000 m3/d or 500 gpm) on the water balance of the aquifer, flow in the Kettle River, and the capture zone areas should be assessd. _ Water supply systems should: o Monitor and assess the performance of their wells and well water quality on an on-going basis; o Actively promote conservative use of water and optimal application of fertilizers; o Renew their efforts to develop, implement and report on well protection plans for their community wells; and o Promote voluntary compliance of closure of abandoned wells and for the City of Grand Forks and Grand Forks Improvement District to consider adopting well closure bylaws for their service areas. _ The Regional District of Kootenay-Boundary and City of Grand Forks should explore how information on the Grand Forks Aquifer can be used to assist in making decisions related to land use and planning for growth to promote the sustainability and protection of the local groundwater. _ The Ministry of Environment should review its Observation Well and Ambient Groundwater Quality Monitoring networks in Grand Forks for adequacy of coverage, operation, and reporting. |
