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What is a Contaminated Site?

Updated: Sep 16, 2021

  • A contaminated site is defined as an area of land in which the soil or underlying groundwater or sediment contains a hazardous waste or substance in an amount or concentration that exceeds numerical levels specified in provincial and federal policies and regulations.

  • A site is contaminated if it is unsuitable for specific uses of land, water and sediment.

  • A site can also be contaminated naturally due to the geology of the area (asbestos or radiation)

Many sites in First Nations in Canada became contaminated during past industrial or commercial uses as well as a result of aging or damaged heating fuel tanks. Such activities often resulted in chemicals and other toxic materials being spilled or deposited on land.

The most common substances found at sites in Canada are heavy metals such as lead, arsenic, cadmium, and mercury. Organic chemicals, including benzene and toluene in gasoline, occur at about two-thirds of the sites. Chlorophenols are common at wood treatment operations, as are benzo[a]pyrene and naphthalene from creosote.

Polychlorinated biphenyls (PCBs) often occur at sites where electrical equipment was used.

In Canada, there are over 23,000 known and suspected Federal contaminated sites, and in Ontario specifically there are over 1,000 sites on First Nations. Petroleum hydrocarbons are especially common on reserve land as many communities rely on diesel generated power and heat. Many First Nations communities are not connected to the electrical grid.

The reliance on diesel fuel for electricity and heat has contributed greatly to the amount of sites contaminated by petroleum hydrocarbons on reserve land. Communities in the North are shown to have more contaminated sites.

This is partly due to the fact that a lot of these communities do not have all season road access making transportation of remediation materials and workers difficult, in comparison to communities with all season road access.

Why are Contaminated Sites a concern?

Contaminants pose a threat to human health, the environment, and safety. Their potential effects on humans range from minor physical symptoms to life-threatening diseases such as cancer. Children are often most at risk from exposure to contaminated soil, air, water, and food.

Even if a site does not pose a threat to people, it can still be an environmental hazard. Soil, water, and sediment at a site may contain substances that can negatively impact fish or mammals; impair the reproduction of birds; and accumulate in the food web.

These effects can be severe enough to impair, or cause imbalance in, ecological functions or systems.

How are Contaminated Sites Identified?

There are several different ways in which potentially contaminated sites can be identified. The majority of these avenues are dependent upon previous investigations and/or reports that may have been generated for the site.

Ways in which a site may be identified without accessing the actual property include:

  1. previous environmental record(s);

  2. internal environmental programs;

  3. complaints by citizens;

  4. off-site impacts;

  5. similarities to other known contaminated sites;

  6. visual or olfactory (smell) evidence of previous leaks, spills or discharges; and

  7. the nature of current or past activities at the site or adjacent properties.

Who is Responsible for Remediating a Contaminated Site?

In Canada, the “polluter pays” principle applies to legal liability in regards to contaminated sites. Therefore, the private company or owners of the property are typically liable for the costs of cleaning up (remediating) the land in which they contaminate. The nature and extent of any liability is not always clear.

Liability depends on many factors, including the location of the contaminated site and the role of the Government of Canada regarding the site.

With regards to the location of the site, under the Constitution and other laws, provinces and territories have authority to make laws regarding property and commerce. As such, responsibility and legislative authority over contaminated sites is primarily the responsibility of the provinces and territories.

With regards to the role or actions of the Government of Canada, there may be liability where it owns, leases or manages contaminated sites - in whole or in part. Similarly, provinces or territories may also be liable under the same circumstances. In some cases, liability may be shared between multiple parties.

In addition, there may be some cases, such as First Nation reserve lands, where the Government of Canada concludes that it is appropriate to assume some responsibility for the contaminated site.

For example, when private companies who caused the contamination have gone out of business or were unable to pay for dealing with these sites and where no governments are legally liable, one or more levels of government have assumed responsibility of these ‘orphan’ sites.

This has occurred in the North and in close proximity to First Nations, where mining companies have gone bankrupt and there is a need to remediate the contaminated site.

Contaminated Sites on First Nations

The Crown exercises a limited amount of environmental regulations through federal laws of general application, such as the Canadian Environmental Assessment Act, the Fisheries Act, the Species at Risk Act, and the Canadian Environmental Protection Act.

However, these laws are not specific to First Nation lands and are of limited use in these locations. The primary legislation through which the Crown exercises its jurisdiction over reserve lands is the Indian Act.

There are no provisions in the Indian Act specific to environmental management of reserve land or the protection of the environment.

The large number of contaminated sites on reserve land can be in a large part attributed to this gap in legislation. The lack of enforcement in regards to environmental issues has caused the remediation process of these sites to be a slow process.

The Indian and Inuit Affairs Program (IIAP) of Crown-Indigenous Relations and Northern Affairs Canada (CIRNAC) is responsible for the Contaminated Sites Management Program.

The program's focus is to provide financial assistance to assess and remediate contaminated sites on reserve lands and determine the location and severity of contaminants on inhabited reserves.

Sites which pose a risk to human and environmental health and safety are ranked by priority and remediated accordingly.

Why is it Important to Remediate Contaminated Sites?

Indigenous people have an inherent interest and responsibility to be stewards of the land and the environment. This encompasses all living and non-living things and understanding each ones importance to life. Related: 3 ways to effectively communicate technical information to First Nations communities

This responsibility extends seven generations into the future, and ensuring the land, air and the water are both healthy to sustain life on Mother Earth. Cleaning up these sites is of significant importance to First Nations people to make sure our children, their children and theirs have access to healthy and safe drinking water and thriving plant and animal life to sustain them.

Want to See a Contaminated Site Return to Pre-use Health in Your Community?

If you or your community has knowledge of a site that has historical federal commercial/ industrial use that is confirmed or suspected to be contaminated and it is the community’s priority to see it remediated, there is funding available from the Federal Contaminated Sites Action Plan (FCSAP) to begin the process.

Many communities have Land Relationship Visions or Environmental Management Plans already in place that may have already identified contaminated sites. Knowing the priorities of the community will help guide the process for contaminated site remediation.

Contact us today about how we can help with your community contaminated site remediation planning needs. Call us at: 705-657-1126 or by email at:

To book a zoom meeting directly with our CEO to discuss how we can help with your contaminated site needs, click here


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