Current Watershed Conditions
Sault Ste. Marie Region Conservation Authority (SSMRCA)
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Groundwater Quality

Two indicators were used to assess groundwater quality:

Nitrite + Nitrate – Although nitrogen occurs naturally in rocks and groundwater, the concentration of nitrogen can be significantly increased by the overuse of fertilizer, spilled manure, and leaky septic systems. Conservation Authorities rely on the Provincial Groundwater Monitoring Network as one source for nitrite + nitrate data.

Chloride – Chloride is a naturally occurring element that can be found in concentrations that exceed drinking water quality standards under natural circumstances, sometimes due to the type of rock the groundwater is coming from. It can be difficult to determine whether high chloride levels are due to natural or human causes.

Threats to Groundwater

Groundwater sources can be threatened by activities such as leaky fuel or chemical storage containers, road salt spreading, spreading of sewage treatment sludge, spilled fertilizers or chemicals such as dry cleaning solvents, accidental spills, septic systems, underground sewers, landfills, manure, or even from overuse. Underground aquifers are recharged mainly by rainfall and snow. As long as the water contained in these aquifers is not extracted faster than it is replenished, groundwater is a renewable resource.

In the Sault Ste. Marie Region Watershed

Concentrations of nitrate and chloride were measured at eight Ontario Ministry of the Environment and Climate Change groundwater monitoring wells.

What Did we Find?

  • Overall concentration of Nitrate + Nitrite in most monitoring wells is classified as excellent (A Grade).
  • Overall concentrations of Chloride in most monitoring wells is classified as excellent (A Grade).
  • Chloride concentrations approach or exceed health standards at one deep aquifer monitoring well resulting in a poorer grade (less than A Grade).
  • Groundwater Quality data for this report has been collected for the Provincial Groundwater Monitoring Network (PGMN) by the Sault Ste. Marie Region Conservation Authority from 2001-2016.

Click on map below to view map

Map of Groundwater Quality showing letter grades of monitoring wells and locations.