Groundwater Protection Plan

The Importance of the Lower Cowichan and Chemainus River Aquifers

Clean groundwater is a vital resource, fundamental to our everyday activities, health, and economic well being, and ultimately, our survival. In the Municipality of North Cowichan, the City of Duncan and the Cowichan Valley Regional District, we obtain our drinking water from the Lower Cowichan River aquifer and the Chemainus River aquifer.

These aquifers, which are natural underground water reservoirs, currently provide excellent quality water. However, contamination of this aquifer is a concern, due to the highly permeable nature of the overlying soils. You can assist the community by taking measures to prevent chemical and waste spills by ensuring that all hazardous materials are transported, stored, and disposed of correctly.

This information has been prepared to assist you in developing practices that will help to preserve the high quality potable water in North Cowichan.

How could the aquifers get contaminated?

Aquifers are composed of permeable layers of rock, sand or gravel, which enable surface waters including streams, rivers, and precipitation to percolate into the ground and recharge groundwater resources.
The aquifers in North Cowichan are particularly vulnerable for several reasons. First of all, the groundwater lies only a few metres below the ground surface, which means that contaminants need to travel only a short distance through the soil to reach it. Secondly, the layer protecting the groundwater from the upper surface consists primarily of highly permeable gravel and sand. Rainfall quickly seeps through the pores of the coarse soil carrying contaminants from the surface to the aquifer below.

What type of contaminants adversely impact our groundwater quality?

  • antifreeze
  • household cleaners
  • detergents
  • fertilizers
  • gasoline and oil
  • manure
  • paints
  • pesticides
  • sewage

What Action Can Be Taken to Protect Our Groundwater?

The following list provides several actions to avoid potential contamination of groundwater:

  • Ensure that handling, storage and disposal procedures for hazardous materials are followed.

    Ensure containers are well sealed to prevent spills.  For more information, contact the manufacturer or supplier from which you purchased the product.

  • Purchase only the amount of chemical products you require.

    Return excess product spills or drips to the original container. Leftover paint, pesticides, flammable liquids, and solvents can be disposed of at the Return-It Centre at 1065 Canada Avenue, or at other approved depots.

  • Never dispose of any hazardous products by dumping these materials on the ground, in storm sewers, open drainage courses, ponds, septic tanks, or garbage cans.

    Wastes spilled or disposed of by these means have the potential to be transported into the groundwater system and to directly impact the local ecosystem (particularly fish, which are often highly sensitive to environmental contaminants).

  • Recycle used oil, solvents and antifreeze.

    Typically, used oil can be returned to the place of purchase or they will direct customers to an alternative facility that has a free return policy. For more information on where to take specific products, refer to the CVRD Recycling Directory or call the CVRD Recycling Hotline at 746-2540.

  • Situate all hazardous waste products and activities, including mixing and storage, on surfaces that will contain spilled materials and prevent them from entering drains or soils.

  • Maintain at hand emergency equipment, such as absorbents and spill kits, ready to contain spills.

    Remember that rags used to clean up spills must be treated as hazardous materials.

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