Canadian Council of Ministers
of the Environment

Le Conseil canadien des ministres
de l'environnement


Contaminated Sites - Canada-wide Standard for Petroleum Hydrocarbons (PHC CWS) in Soil

Petroleum hydrocarbons (PHC) are one of the most widespread soils contaminates in Canada and consist of a wide range of organic compounds found in or derived for geological sources such as oil, coal and bitumen, including a variety of raw and refined fuels and lubricants.  PHC released to the environment are complex mixtures, typically continuing thousands of compounds, in varying proportions. PHC contamination can cause a wide variety of problems related to their toxicity, mobility and persistence, including potential for fire/explosion hazard, toxicity to some degree for human/or environmental health, transportation of lighter PHC by groundwater or air, persistence of larger branched-chain PHC in the environment, aesthetic problems such as offensive odour, taste or appearance in air and water, degradation of soil quality that interferes with water retention and flow of nutrient supplies to plants.

The Canada-Wide Standard for Petroleum Hydrocarbons in Soil (PHC CWS) is a remediation standard that sets out the levels to which PHC impacted sites must be cleaned up to – if and when they are subject to remediation.  The PHC CWS sets out generic target levels, as well as a process for generating site-specific numbers based on risk that are protective of human and ecological health. The PHC CWS was endorsed by ministers in May 2001 and revised in January 2008 after an extensive review.