Site Investigation staff members perform different tasks and types of assessments with varying levels of detail, depending on the severity of the situation.
Hazard Ranking System
The staff utilizes the U.S. Environmental Protection Agency’s (U.S. EPA) Hazard Ranking System to determine the relative risk at a site based on prior assessments and investigations that revealed contaminants at elevated levels. Through a series of analyses and data gathering activities, the staff calculates a score that represents the relative risk at a site based on issues such as the types of pollution sources, the containment of those sources, and existing or potential targets that could be affected by contamination associated with the site. A site must have a score at or above 28.50 in order for it to qualify for placement on the National Priorities List (NPL) of sites that qualify for federally funded long-term cleanups.
Pre-Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Screening Assessments
OLQ screens all referred sites to determine which ones qualify for further assessment before they are entered into the Superfund Enterprise Management System (SEMS). In this way Pre-CERCLA screening can reduce the number of sites unnecessarily entered into SEMS. Screenings also provide a useful tool in assuring that those sites that are entered into SEMS are further assessed for their risks to human health and the environment. OLQ then determines whether federal response action is needed.
Preliminary Assessment
A Preliminary Assessment is a limited-scope investigation that is designed to distinguish between sites that pose little or no threat to human health or the environment and sites that require additional investigation and sampling. It includes a site visit and collects readily available information about a site and its surrounding area.
Site Inspections and Expanded Site Inspections
If a Preliminary Assessment has determined that additional investigation and sampling is necessary, a Site Inspection is performed. It typically collects environmental samples to determine the contaminants present and whether they are being released into the environment. The objective is to identify sites that have a high probability of qualifying for the NPL or pose an immediate health or environmental threat which requires an emergency response. If the site is likely to qualify for the NPL, then an Expanded Site Inspection is conducted to obtain additional information.