Regional Scale Groundwater Study

Renfrew County - Mississippi - Rideau

A groundwater study has recently been conducted.  The goals of this work were to:
  • develop a database and GIS as an aid to analysis, interpretation, and management
  • undertake a regional water balance
  • map aquifers locations, recharging/discharging areas, flow systems, and quality conditions
  • assess surface water quality
  • inventory groundwater users and assess the demand on aquifers
  • map areas where aquifers are susceptible to contamination
  • identify known and potential contaminant sources
  • identify guidelines (all three levels of government) and regulations to protect groundwater
The study can be viewed from the following website,

With respect to the Tay River watershed, the following comments can be made:
  • Precambrian rock is the main aquifer in the watershed, and vertical fractures predominate
  • sedimentary rocks are more common in the east, with horizontal fractures and horizontal bedding planes
  • Precambrian rock aquifers are more susceptible to potential contamination since the majority of the area has shallow (<2 m) overburden
  • groundwater discharge (baseflow) provides most of the water to streams during the summer and winter months and, thus, has an important role in sustaining natural habitats
  • esker-like overburden deposits in areas of high elevation may act as sources of groundwater recharge
  • the most common water problems result from chloride and nitrate contamination
  • 61% of Lanark County residents use groundwater for drinking, compared with 23% in the larger study area
  • the total volume of groundwater taken (permits +) is less than 2% of what is potentially available from recharge
  • known contaminant sources include petroleum products, chlorinated solvents, landfill leachate, and septic tanks
  • provincial regulations at the present time do not provide clear authority for a municipality to control or protect groundwater

contact Friends of the Tay Watershed