Calgary, Canada (GLOBE-Net) - Alberta Environment has released the draft Tier 2 Eco-contact Guideline Derivation Protocol for public review and comment. This document provides a protocol for developing site-specific eco-contact guidelines for petroleum hydrocarbons.

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).

The document:

• 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:

Gordon Dinwoodie
Environmental Policy Branch
Alberta Environment
10th Floor, 9820 - 106 Street
Edmonton, Alberta
T5K 2J6 
Gordon.Dinwoodie@gov.ab.ca

Source: Government of Alberta .