In Canada, sites requiring soil remediation are classified based on the Canadian Council of Ministers of the Environment (CCME) National Classification System for Contaminated Sites (NCSCS). The classification provides scientific and technical guidelines in order for the parties responsible for the site (departments, agencies and Crown corporations) to score the level of pollution from high, medium and low risk for human health and the environment (Environment and Climate Change Canada, 2019j). Within the FCSAP sites with higher risk are considered as a priority. The cost for site remediation is the responsibility of the current property owner who could seek damages from past owners if they caused the pollution, according to the polluter pays principle. As such, the federal government is responsible for the remediation cost of sites it owns or leases, or responsible in part. In case, a private company is not able to pay the expenses of remediation (ex. bankruptcy, etc.) and no local government is legally liable, the Government of Canada takes the responsibility of the orphan site (Environment and Climate Change Canada, 2019k).
To facilitate the remediation of government owned polluted sites, Canada announced a renewed investment of the Federal Contaminated Sites Action Plan (FCSAP) from 2020 until 2034, with an initial investment of USD 1.16 billion for the next five years. The aim of the investment is to continue in the remediation efforts of federal polluted sites. With the funding renewal, it was estimated that 242 sites will be assessed, and 1 316 sites will be remediated, including sites located within First Nation reserves. The previous Federal Contaminated Sites Action Plan launched in 2005, helped with the remediation of 2 200 polluted sites and the assessment of 10 960 sites across Canada (Environment and Climate Change Canada, 2019k).
To prioritize the remediation of sites with high environmental impact the United States EPA has created a Hazard Ranking System (HRS) under its CERCLA legislation. The HRS generates a score using a numerical system based on information from initial investigations and input from US EPA, state officials, tribal or other federal agencies. A score of 28.5 or above is the threshold for inclusion on the National Priority List (NPL) and priority for clean-up and funding through the Superfund process (US EPA, 2018g). Under Superfund, EPA is responsible for identifying the parties responsible for the toxic releases into the environment and insuring their cooperation for the cleanup. EPA forces the parties to clean up the sites through agency orders, consent decrees or legal settlements. When the responsible party no longer exists or is unable to fund the cleanup, the Superfund trust fund may provide funding (US EPA, 2019o).
A priority in the United States of America and Canada is the widespread pollution of potable water and soils from per- or polyfluoroalkyl substances (PFAS), which includes a family of thousands of chemicals, such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), among others. To date, PFAS pollution has been detected in the tap water of 2 230 communities across the United States of America, including 300 military sites (EWG, 2019a; US EPA, 2018f). PFOA and PFOS, which were the most widely used and studied, are no longer manufactured in the United States of America and Canada but industry continues to use chemically similar compounds. The largest share of PFOS and PFOA was used on carpets, textiles, furniture and food contact paper like fast foot wrapping and pizza boxes from 1970 to 2000 (Fricke and Lahl, 2005) and has been largely disposed to landfills the last four decades. The release of PFAS from municipal waste landfills in the United States of America is estimated to 500 kg/year (Lang et al., 2017). Considering that tens of thousands of tonnes of PFAS were disposed in landfills, this release will likely continue for centuries since PFAS are more persistent than the containment systems of landfills (Li et al., 2017; Weber et al., 2011). The historic production and use of PFOS alone was over 96,000 tonnes with the largest share produced and used in the United States of America (Paul, Jones and Sweetman, 2009). Imported consumer goods such as carpets, leather, textiles, paper and packaging, coatings, rubber and plastics are still a source of PFAS chemicals that replaced PFOA and PFOS and likely have similar toxic properties (EWG, 2019b; US EPA, 2018f).
The US EPA has developed a PFAS action plan in order to identify and understand PFAS, to address the already polluted sites with PFAS, prevent future pollution and communicate to the public about PFAS (US EPA, 2019r). Federal and state environmental agencies are providing funding to research the extent of PFAS pollution, fate and transport, and drinking water filtration technologies (US EPA, 2019s). Canada’s regulatory response is also developing (Health Canada, 2017b).
Abatement of lead-based paint hazards in homes and surrounding soil is an ongoing priority in both countries based on established science showing its detrimental lifelong impacts. The United States of America Department of Housing and Urban Development annually offers grants to communities to mitigate lead paint hazards in homes and surrounding soil. In 2020, USD 275 million was available through this source for which soil remediation was eligible (HUD, 2020).