Protocol for the Derivation of Environmental and Human ... - CCME

Part A, Section 1
Establishing remediation objectives for a specific site may require adopting the national environmental
quality guidelines unchanged. However, to accommodate some site conditions (i.e., physical soil
conditions, background contaminant concentrations and potential ground water contamination), the
guidelines may be modified without a complete risk assessment. The site-specific information may
identify remediation objectives which are more or less stringent than the generic guidelines. Potential
cost, technological feasibility, and potential contaminant receptors may also be necessary considerations
before setting remediation objectives.
Guidance on setting site-specific objectives by adapting generic guidelines is provided in the Guidance
Manual for Developing Site-specific Soil Quality Remediation Objectives for Contaminated Sites in
Canada (CCME, 1995). While technical, social, and economic issues are important to the overall site
remediation plan, these issues are beyond the scope of this document. The availability and cost of
suitable remediation technology, public consultation, and the aesthetics of remediation technology,
should be addressed by the agency responsible for the remediation plan.
1.2.4 Guidance on Human Health and Ecological Risk Assessment
When site-specific physical, chemical, or biological considerations are beyond the scope of generic
guidelines, a site-specific ecological and/or human health risk assessment may be recommended to
define site-specific cleanup objectives. This is called the "risk-based approach" for achieving sitespecific
objectives in Figure 1.
A risk assessment may be recommended:
• if levels at the site exceed the generic remediation guidelines;
• if there are receptors of concern;
• if there are sensitive or extraordinary site conditions (e.g., critical habitat or lack of contaminant
attenuation mechanisms);
• if there are data gaps;
• if there are other factors (e.g., socio-economics, technological limitations or public
perception/consultation); or
• if there are regulatory concerns.
The Guidance Documents on Ecological Risk Assessment (CCME, 1995 b,c,d) and Human Health
Risk Assessment (Health Canada, 1995a) assist a risk assessor or regulator in successfully completing a
site-specific risk assessment. The documents focus on the essentials of risk assessment (problem
formulation, exposure analysis, toxicity analysis, risk characterization) and describes in detail how to
conduct contaminated site evaluations. The documents also examine site investigation, communication,
risk management, remediation, and monitoring. These documents outline the fundamental requirements
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