The Canada-Wide Standard (CWS) for Petroleum Hydrocarbons (PHC) in Soil is a remedial standard which specifies consistent methods and outcomes for assessment and management of sites contaminated by PHC.

The Canada-Wide Standard (CWS) for Petroleum Hydrocarbons (PHC) in Soil, endorsed by ministers in May 2001, was revised in January 2008 after an extensive review.

Key Changes:

• The human soil ingestion and dermal contact pathways were combined, consistent with the current protocol.
• Modifications were made to several fate and transport model parameters to reflect current science.
• Ecological soil contact values were updated based on further toxicity testing and field studies conducted since the PHC CWS was implemented.
• Subsoil tables were removed from most of the Canada-Wide Standard reports due to differences in implementation between jurisdictions and concerns regarding the approach taken.  In their place, management limits were developed that have explicitly stated considerations that were previously incorporated into the subsoil ecological guidelines.  Subsoil tables were included in the technical supplement to maintain consistency with the 2001 Canada-Wide Standards.
• Consistent with the 2001 Canada-Wide Standards, surface terrestrial ecological criteria will contine to apply for all sites between 0 and 1.5 meters below ground level.  For depths greater than 3 meters below ground level, a management limit was developed that may be applied in place of the surface ecological soil criteria.  Due to jurisdictional differences in interpreting requirements for management practices, no guidance is given for depths between 1.5 and 3 meters below ground surface.  Guidance for application of the criterial may be developed by the jurisdiction for these depths.