Changes to Alberta Tier 1 Soil and Groundwater Remediation Guidelines for Human Health for Dioxins and Furans Explained

Alberta Environment and Protected Areas (EPA) released an update to the Alberta Tier 1 Soil and Groundwater Remediation Guidelines on June 27, 2024. As part of that update, changes were made to the Alberta Tier 1 Soil and Groundwater Remediation Guidelines for dioxins and furans. The changes are based on the findings of a panel commissioned by Alberta EPA and Alberta Health to review the Alberta Tier 1 Soil and Groundwater Remediation Guidelines for human health from exposure to dioxins and furans, and the recommendations from the Scientific Working Group for Contaminated Sites in Alberta (SWGCSA) that is comprised of members of Alberta EPA, Alberta Health, the Alberta Energy Regulator and Alberta Health Services.

The changes to the Alberta Tier 1 Soil and Groundwater Remediation Guidelines for dioxins and furans are summarized in the table below.

Changes to Alberta Tier 1 Soil and Groundwater Remediation Guidelines in 2024

Exposure Pathway	Value
	2022	2024
Human Health Direct Soil Contact (mg/kg)
·         Agricultural	0.0000040	0.000054
·         Residential	0.0000040	0.000054
·         Commercial	0.0000040	0.000080
·         Industrial	0.0000040	0.000118
Drinking Water (mg/L)	0.00000012	0.000000016 (only if NAPL is present)

Notes: mg/kg = milligram(s) per kilogram; mg/L = milligram(s) per litre; NAPL = non-aqueous phase liquid

The basis of the changes to the human health direct soil contact guidelines for dioxins and furans is illustrated in the figure below.

The drinking water guideline for dioxins and furans decreased because of the new TDI and AF (consistent with those used in the calculation of the direct soil contact shown above) but is only applied if non-aqueous phase liquid or NAPL containing dioxins and furans may be present within a drinking water aquifer.

For further details regarding the changes to the Alberta Tier 1 Soil and Groundwater Remediation Guidelines for human health from exposure to dioxins and furans, please contact Christine McFarland at or e-mail . Intrinsik Blogger: Christine McFarland.