Try the new

Source Protection - Background Information

Water Sources and Human Activity


Source Protection is a preventative approach that safeguards our drinking water sources from contamination or overuse by managing human and natural activities which impact the quality and quantity of water.

Our water comes from two major sources: surface water and groundwater. Surface water includes lakes, rivers, streams and wetlands. Groundwater includes water found in soil and cracks in underground rock or aquifers. These two sources of water are interconnected - each affects the other.

We do not have an infinite supply of fresh water.  Most of the water we use is recycled though the natural water cycle:

  • Water falls to earth as precipitation.
  • It is absorbed by plants and the ground, or runs off to streams, rivers and lakes.
  • It evaporates back into the atmosphere.
  • The cycle begins again.
Human activity/land use practices, natural contaminants and climate change, all have the potential to negatively impact the quality and quantity of both surface and groundwater. As ground and surface water sources are interconnected through the water cycle, contamination or depletion of one source will affect the other source, as illustrated in Figure 1. 

top of page

Figure 1: Sources of Groundwater Contamination

Sources of groundwater contamination

top of page

What Are Threats to Drinking Water Sources?

Under the Clean Water Act, 2006, there were 21 drinking water threat activities identified by the Ministry of the Environment that will be addressed through Source Protection Plans. Examples of municipal drinking water threat activities include, but are not limited to, the following:
  • The application, handling and storage of commercial fertilizers to land.
  • The application, handling and storage of pesticides to land.
  • The application, handling and storage of road salt.
  • The establishment, operation, and maintenance of septic systems.
  • The application, handling and storage of agricultural and non-agricultural source material.
  • Livestock confinement and grazing.
  • The handling and storage of fuel.
  • The handling and storage of chemicals.

top of page