Alberta Tier 2 Eco-contact Guideline Protocol
Under Alberta’s contaminated sites management framework, three options are provided for the management of contaminated sites as the proponent proceeds from initial site assessment to regulatory closure:
- Tier 1 - generic remediation guidelines.
- Tier 2 - site-specific remediation guidelines based on the modification of Tier 1 guidelines.
- Exposure Control - risk management through exposure barriers or administrative controls based on site-specific risk assessment.
Tier 1 soil remediation guidelines (AENV, 2007a) include guidelines for the protection of ecological receptors that are exposed to soil contamination by direct contact. The eco-contact guidelines for petroleum hydrocarbons (PHC) are based on a series of laboratory soil ecotoxicity tests performed during the development of the CCME Canada-Wide Standard for Petroleum Hydrocarbons in Soil (CCME, 2007).
In some cases, the Tier 1 eco-contact guidelines may be overly conservative relative at sites where (i) the bioavailability of PHCs to soil-associated flora and fauna is considerably less than 100%, or (ii) the bio-available fraction of PHC mixture in the soils exhibits low toxicity in comparison to the toxicity expressed under the conditions of the CCME bioassay testing.
Under these conditions, Tier 2 remediation guidelines (AENV, 2007b) may be developed that will provide a site-specific remediation objective that provides the same level of protection envisioned by the Tier 1 guidelines.
This document provides guidance on the development of Tier 2 guidelines for PHC contaminated soils based on protection of soil ecological functioning (eco-contact pathway).
The protocols described are based on CCME (2006, 2007), Environment Canada (2004, 2005a, 2005b) and Stantec Consulting (2005).
- Describes conditions under which a Tier 2 approach may be considered;
- provides the detail required to plan and execute the field bulk soil sampling;
- describes the minimum requirements and suggestions for the laboratory testing program; and
- touches on data analysis and statistical considerations specifically related to the determination of a Tier 2 pass, and the establishment of a Tier 2 Provisional SSRO, as desired.
The Tier 2 Eco-contact Guideline Derivation Protocol is available here.
Please forward comments on or before September 28, 2007 to:
Environmental Policy Branch
10th Floor, 9820 - 106 Street
Source: Government of Alberta .