Responding to growing concern over public health and environmental threats from
uncontrolled releases of hazardous substances, Congress passed the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) in 1980. CERCLA,
popularly known as Superfund, established a comprehensive program to identify and
clean up hazardous substance spills and contaminated sites. The Environmental Protection
Agency (EPA) was given the responsibility to implement the Superfund program at
that time.
In 1980, it was believed that relatively few sites in the nation were
contaminated with hazardous substances. Superfund was supposed to be a short-lived
program involving at most a few hundred sites requiring relatively few resources.
However, as EPA began discovering sites and evaluating their potential harm, the
inventory of hazardous substance sites grew rapidly. At one time, more than 36,000
sites were on the EPA’s computerized data base of hazardous substance sites, and
more than 1,200 were placed on the National Priorities List (NPL) of the most hazardous
sites. Since 1980, the states have assumed more and more responsibility for the
implementation of the Superfund program.
One of the primary functions of the Superfund program in the Hazardous Waste
Division is to perform site assessment activities for placement of properties on
the NPL. The site assessment process is multi-phased. After site discovery, a Preliminary
Assessment (PA) is performed for initial data gathering. Information on site history,
waste types, routes of contaminant migration and exposure pathways is obtained.
Following the PA phase, if warranted, a Site Inspection (SI) may be performed.
During the SI, environmental samples are collected from potentially impacted media,
including surface water, ground water, soil and air. Additional data is also collected
regarding human and ecological receptors potentially at risk.
An Expanded Site Inspection (ESI) may be conducted after the SI phase in order
to collect very focused data. For instance, during an ESI, additional ground water
monitoring wells may be installed or a wetland delineation may be performed. An
ESI is not always warranted.
Information collected during the PA, SI and ESI is further evaluated via the
EPA’s Hazard Ranking System (HRS). The HRS assigns a numerical value to specific
characteristics of the site, including waste types, waste volumes, and human and
ecological receptors potentially at risk. A site must score 28.5 or greater on an
HRS score to be placed on the NPL.
Since the inception of the Superfund program in 1980, 13 sites in Arkansas have
been placed on the NPL as a result of the site assessment process and HRS ranking.
Five sites have since been removed from the NPL. The Arkansas
Department of Environmental Quality (ADEQ) functions as a support agency to EPA
for work performed on 10 of these sites. On two NPL sites (Midland Products and
Monroe Auto), ADEQ functions as the lead agency. For a complete list of Superfund
sites in AR, please visit the
EPA Region 6 Superfund page for Arkansas.
