Comparing ecological risk assessments (ERAS) at diverse Superfund sites using the EPA framework

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:40155

Bahl, A A; Burns, T P; Cornaby, B W; Hadden, C T; Tischier, M L ^[1]

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1. Science Applications International Corp., Oak Ridge, TN (United States). Engineering and Environmental Compliance Group

ERAs at Superfund and other hazardous waste sites provide a detailed picture of how EPA`s Framework can be used to assess risk at sites for which ecological data are limited or unavailable. Four interrelated ERA activities -- problem formulation, exposure assessment, effects assessment, and risk characterization -- were applied at several sites in Tennessee, New Jersey and Ohio. The authors present innovative techniques for defining data quality objectives (DQOS) and assessment and measurement endpoints, screening contaminants of potential concern (COPCS) and comparing the relative risk to ecological receptors. A rationale for defining and determining thresholds, and screening COPCs was utilized. Screening steps identify COPCs by comparisons to background concentrations, frequency of occurrence, mobility, persistence, and toxicity thresholds. Conservative toxicity thresholds are established using government standards, published ``no effect levels``, chronic test endpoints and acute test endpoints. Mobility and persistence of a COPC are considered in the screening process, recognizing the potential for contaminants to migrate, bioconcentrate or degrade. Exposure factors are derived for major exposure pathways for groups of organisms with similar modes of exposure. These factors are then multiplied by the source contaminant concentrations and divided by the appropriate toxicity thresholds to give an exposure quotient (XQ) for each pathway which is summed for those exposure classes with multiple pathways. This method identifies the COC-exposure unit-ecological receptor class triads associated with the highest risks. These innovative techniques have proven to be adaptable to site-specific properties while preserving consistency with EPA`s Framework and permitting decisions to be made.

• OSTI ID: 40155
• Report Number(s): CONF-9410273--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ENVIRONMENTAL EXPOSURE PATHWAY
ENVIRONMENTAL IMPACTS
HAZARDOUS MATERIALS
NEW JERSEY
OHIO
REMEDIAL ACTION
SANITARY LANDFILLS
TENNESSEE
TOXICITY
US SUPERFUND