Supplier
EPA
Years Available
2002 - present
Periodicity
Annual or more often
Description
Thousands of contaminated sites exist nationally due to hazardous waste being dumped, left out in the open, or otherwise improperly managed. These sites include manufacturing facilities, processing plants, landfills and mining sites. In 1980, Congress established the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). CERCLA, informally called Superfund, allows the U.S. Environmental Protection Agency (EPA) to clean up contaminated sites. It also forces the potentially responsible parties (PRPs) found liable for the contamination to either perform cleanups or reimburse the government for EPA-led cleanup work. Superfund program data are tracked within the EPA's Superfund Enterprise Management System (SEMS) database. Human exposure data are publicly available via the Superfund Program's Site Profile Pages, the Superfund Program's Human Exposure Dashboard, and in the EPA's Report on the Environment (ROE) and Superfund’s Annual Accomplishment report. SEMS tracks Superfund final and deleted National Priorities List (NPL) sites and sites with Superfund Alternative Approach (SAA) agreements in place within the Environmental Indicator (EI) site baseline. Using a structured, published process, the EPA can determine whether humans may be exposed to contamination in excess of health-based standards, providing a site-wide status of either human exposure under control (HEUC), human exposure not under control (HENC) or insufficient data to determine human exposure (HEID). The data are collected and managed by EPA's Office of Superfund Remediation and Technology Innovation (OSRTI). They are also reported through the ROE program and are available for download from the ROE website. For real-time Human Exposure determinations for Superfund sites, visit EPA's Human Exposure dashboard.
Population Covered
Final and deleted Superfund NPL sites and sites with SAA agreements.
Methodology
EPA staff complete a flow chart and questionnaire based on data and conclusions from Superfund documents such as Remedial Investigation/Feasibility Studies reports, Records of Decision, Action Memoranda, Pollution Reports (POLREPS), Remedial Action Reports, Close Out Reports, Five-Year Reviews, Deletion Notices, etc., which are known and reliable sources of information. EPA staff document these sources of information used to make the evaluation in SEMS.
The data are compiled for ROE by EPA's Office of Superfund Remediation and Technology Innovation, who collect the following information on each site:
1) Contaminant concentrations in media (e.g., Land, air, water, land, sediment, biota)
2) Site-specific observations regarding human exposure via exposure pathways
3) Findings from human health risk assessments.
It is indicated whether there are complete exposure pathways between contaminated media and current human receptors (exposure assessment) and, if so, whether the complete exposure pathways represent unacceptable risk (risk characterization).
EPA tracks exposure indicators at each Superfund site. These indicators are classified into three categories:
1) Current human exposures not under control
2) Current human exposures under control
3) Insufficient data.
The third category covers sites that have been classified as having "insufficient data" to make a determination.
Interpretation Issues
NPL and SAA sites do not represent all the contaminated or potentially contaminated sites in the United States. EPA also tracks some information on potential hazardous waste sites and remedial activities across the nation. Concentrations of toxic and hazardous contaminants that result in designation of a site as having or not having human exposures to contamination in excess of health-based standards vary from state to state, although they fall within a range determined to be acceptable to EPA. The indicator is based on certification by a responsible official that the criteria necessary to designate a site as having or not having human exposures to contamination in excess of health-based standards have been met. The approach may not take into account certain risks (e.g., endocrine disruptors) where specific risk levels (e.g., to human health) may not have been established.
Limitations
During each fiscal year, the Superfund program lists new sites on the National Priorities List (NPL)—usually those new sites are not "Under Control" when added. The new site's "human exposure status" are not added to the baseline to start tracking until the following year. Thus the data are only directly comparable year-to-year.
