New Soil and Groundwater Guidelines for PFOS

November 22, 2021


Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) have received a lot of attention over recent years due to their toxicity, mobility, widespread occurrence, and stability in the environment. The Canadian Council of Ministers of the Environment (CCME) recently announced soil and groundwater quality guidelines for one of the most important PFAS compounds, Perfluorooctane Sulfonate (PFOS).


The CCME guidelines include pathway-specific guidelines for PFOS in both soil and groundwater, but due to its mobility and toxicity, the drinking water guideline (0.0006 mg/L) will be the risk driver for most sites. The PFOS drinking water guideline is orders of magnitude lower than many other common or higher-risk contaminants of concern (examples below) and likely to decrease over time, which is consistent with trends in other jurisdictions.

Contaminant CCME or CDWQ guideline
PFOS 0.0006 mg/L
Benzene 0.005 mg/L
Sulfolane 0.09 mg/L
Arsenic 0.01 mg/L

With the CCME guidelines in place, there are now Canadian soil and groundwater reference guidelines for assessing and remediating PFOS-contaminated sites. Locations this is most likely to affect include:

  • Sites where AFFF (Aqueous Film-Forming Foams) may have been used (e.g., fire training facilities, airports, etc.)
  • Wastewater treatment facilities
  • Landfills
  • Oil and gas facilities

Why is this important?

We anticipate that these guidelines will be adopted by provincial regulators where the guidelines don’t already exist. When that happens, it may trigger additional contamination management measures, starting with assessment to confirm the presence or absence of PFOS at higher risk sites. For Alberta, it is expected that the PFOS guidelines will be adopted with the next Tier 1 Soil and Groundwater Remediation Guideline update that is expected to occur towards the end of 2021 or in early 2022.

Matrix Experience / How can Matrix Solutions help?

Sampling for PFAS is complex due to the extremely low detection limits and guidelines, and high potential for cross contamination. Matrix has developed detailed PFAS sampling procedures and our teams have experience sampling, analyzing, and interpreting PFAS data. If the guidelines do result in contamination management triggers, Matrix will be able to help by assessing and designing plans to manage the risk, specifically:

  • Identifying potential sources
  • Characterizing hydrogeology and contaminant transport
  • Designing targeted assessment programs
  • Completing screening-level assessment programs
  • Designing and implementing monitoring programs

More information

For more information on our Assessment, Remediation, and Risk Management solutions, click here.

Blake Hamer
Principal Contaminant Hydrogeologist

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