Canadian Water and Wastewater Association eBulletin

Alberta: Directive Alerts Thermal In Situ Approval Holders About Dangers Of Increased Levels Of Arsenic In Groundwater

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Alberta Environment and Parks (AEP) recently issued a new directive requiring companies to assess the impact of increased arsenic levels in groundwater in or around thermal in situ oil sands. Innocuously titled "Draft directive for the assessment of thermally-mobilized constituents in groundwater for thermal in situ operations," the 24-page document notes:

"As thermal in situ oil sands production became established in the late 1990s, increased levels of arsenic were observed in groundwater down gradient of several steam injection wells. These elevated arsenic concentrations have been attributed to the heating of subsurface sediments and subsequent release of arsenic to groundwater.

"Ongoing monitoring at these sites has provided preliminary information about this phenomenon and additional studies have reported similar behavior for other constituents. Similar effects to groundwater are anticipated for in situ projects under certain geochemical and hydrogeological conditions.

"Given the mobilized constituents are naturally-occurring in the sub-surface, such effects are manageable if they are contained within a limited area, do not impact receptors, and are reversible over the long-term. Careful monitoring and management shall be implemented to ensure this.

" Approval holders maintain the responsibility to understand the impact of their operations on the environment and to manage any potential impacts. 

"The management of thermal impacts to groundwater quality is governmed by the precuationary principle and is intended to be adaptable as this knowledge increases. The Directive was developed to improve understanding of the thermal mobilization of constituents in groundwater and ensure that appropriate monitoring and management occurs through the ... implementation of site-specific Project Assessments and Groundwater Management Plans (GMPs).

Stakeholder engagement on the document remains open until May 29, 2016. 


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