Clean Water Act Requirements for Surface Water
The CWA established the basic framework for regulating discharges of pollutants into the water bodies of the United States and regulating quality standards for surface waters. Under the CWA, EPA has implemented pollution control programs such as setting wastewater standards for industry and also developed national water quality criteria recommendations for pollutants in surface waters. Unless a National Pollutant Discharge Elimination System (NPDES) permit is obtained, it is unlawful to discharge pollutants to waters of the United States.
Both on-site and off-site direct discharges from CERCLA sites to surface waters are required to meet the substantive requirements of the NPDES program. These substantive requirements include discharge limitations (both technology and water- quality based), certain monitoring requirements, and best management practices (BMPs) (U.S. EPA 1988).
Safe Drinking Water Act Requirements for Groundwater/Surface Water
The MCLs set under the SDWA are generally the applicable or relevant and appropriate standard for cleanup of groundwater or surface water that is, or may be, used for drinking. A standard for drinking water more stringent than an MCL may be needed in special circumstances (e.g., the presence of multiple contaminants in groundwater or the presence of extraordinary risks due to multiple pathways of exposure). For such cases, Maximum Contaminant Level Goals (MCLGs), the agency’s policy on the use of appropriate risk ranges for carcinogens, levels of quantification, and other pertinent guidelines, should be considered in setting up the cleanup goals.
Clean Air Act Requirements for Air
Remedial activities during a CERCLA cleanup may be sources of air emissions of gas or particulate matter. Examples include handling of contaminated soil, soil vapor extraction of contaminated soil, air stripping of contaminated groundwater, thermal destruction of contaminated sludge and air, as well as bioremediation of contaminated soil and groundwater.
The CAA is to protect and enhance the ambient air quality. The potential ARARs relevant to the CAA include National Ambient Air Quality Standards (NAAQS), National Emission Standards for Hazardous Air Pollutants (NESHAPs), and New Source Performance Standards (NSPS). The six criteria pollutants under the NAAQS are carbon monoxide, lead, nitrogen dioxide, particulate matter (PM10 and PM25), ozone, and sulfur oxides. The original list under NESHAPs included 189 hazardous air pollutants (HAPs); since 1990 the EPA has modified the list through rulemaking to 187 HAPs. The majority of the 187 HAPs are volatile organic compounds (VOCs), which are common soil and groundwater pollutants. The purpose of NSPS is to ensure that new stationary sources are designed, built, equipped, operated, and maintained to reduce emissions to a minimum (U.S. EPA 1989). In addition to federal regulations, a number of state air pollution control agencies have adopted programs to regulate toxic air pollutants.
RCRA Requirements for Air
RCRA regulations covering hazardous waste air emissions include (1) controls on incinerators; (2) requirements for controlling windblown fugitive PM from landfills, waste pipes, and treatment facilities; and (3) organic air emissions from TSDFs (U.S. EPA 1989).
Toxic Substance Control Act (TSCA) Requirements
Under the Toxic Substances Control Act (TSCA), the EPA evaluates potential risks from new and existing chemicals and acts to address any unreasonable risks that chemicals may have on human health and the environment. Of these, the regulations controlling hazardous chemicals are potential ARARs for CERCLA actions. For example, the EPA has published regulations or is taking actions pertaining to polychlorinated biphenyls (PCBs), per- and polyfluoroalkyl substances (PFAS), lead, mercury, and asbestos.
Other Potential ARARs
Other potential ARARs for CERCLA actions are requirements of the Federal Insecticide, Fungicide, and Rodenticide Act, National Environmental Policy Act (NEPA), National Historic Preservation Act, Archeological and Historic Preservation Act, Endangered Species Act, Wild and Scenic Rivers Act, Fish and Wildlife Coordination Act, Coastal Zone Management Act, Wildness Act, Surface Mining Control and Reclamation Act, and standards for the cleanup of radioactively contaminated sites and buildings (U.S. EPA 1989).