• Removal actions are usually short-term actions designed to stabilize or cleanup a hazardous site that poses an immediate threat to human health or the environment.
• Remedial actions are generally longer-term and usually more costly actions aimed at a permanent remedy.
• There are three primary types of ARARs chemical-specific, location-specific, and action-specific.
• ARARs are identified on a site-by-site basis.

Every Superfund site is unique, and thus cleanups must be tailored to the specific needs of each site or hazardous substance release. By law, the Environmental Protection Agency (EPA) may respond with enforcement or Trust Fund- financed removal actions or remedial actions, collectively known as response actions. No matter the response action taken, the chosen management standards and cleanup levels must be protective, based on a site-specific risk assessment, and, for on-site response actions, consistent with state and federal “applicable or relevant and appropriate requirements” identified for the site.

Removal actions

In emergency situations, the respondent (EPA, another federal/state/local agency, or a potentially responsible party (PRP)) will conduct a “removal” action to eliminate the threat. Removal actions are usually short-term actions designed to stabilize or cleanup a hazardous site that poses an immediate threat to human health or the environment. Also, removal actions are conducted in response to accidental releases of hazardous substances. Typical removal actions include:

• Removing tanks or drums of hazardous substance on the surface,
• Installing security measures such as a fence at a site, or
• Providing a temporary alternate source of drinking water to residents.

Remedial actions

At sites where the threat is less immediate, the respondent will perform more extensive investigations to determine the appropriate “remedial” alternatives. Remedial actions are generally longer-term and usually more costly actions aimed at a permanent remedy. EPA may use Trust Fund monies for remedial construction only at sites on the National Priorities List (NPL). The NPL is EPA’s list of the nation’s priority hazardous waste sites. Typical remedial actions may include:

• Removing buried drums from the site,
• Thermally treating wastes,
• Pumping and treating groundwater, and
• Applying bioremediation techniques or other innovative technologies to contaminated soil.

Applicable or relevant and appropriate requirements

Within the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), Congress essentially translated into law EPA’s policy to use other environmental laws to guide response actions. CERCLA 121(d) stipulates that the remedial standard or level of control for each hazardous substance, pollutant, or contaminant be at least that of any applicable or relevant and appropriate requirement (ARAR) under federal or state environmental law.

For instance, regulations promulgated under the Resource Conservation and Recovery Act (RCRA), Clean Air Act (CAA), Clean Water Act (CWA), and Safe Drinking Water Act (SDWA) frequently affect removal and remedial actions. Laws and requirements enforced by agencies other than EPA may also be applicable or relevant and appropriate at a Superfund site.

Environmental laws and regulations fit (more or less) into three categories: (1) those that pertain to the management of certain chemicals; (2) those that restrict activities at a given location; and (3) those that control specific actions. There are therefore three primary types of ARARs:

• Chemical-specific ARARs are usually health- or risk-based restrictions on the amount or concentration of a chemical that may be found in or discharged to the environment. Examples include RCRA land disposal restrictions (LDR) treatment standards and SDWA maximum contaminant levels (MCLs).
• Location-specific ARARs prevent damage to unique or sensitive areas, such as floodplains, historic places, wetlands, and fragile ecosystems, and restrict other activities that are potentially harmful because of where they take place. RCRA, for example, prohibits the placement of hazardous waste in geologically unstable areas.
• Action-specific ARARs are activity or technology based. These ARARs control remedial activities involving the design or use of certain equipment or regulate discrete actions. The decision to dispose of a waste contaminated with polychlorinated biphenyls (PCBs) could, for example, trigger requirements under the Toxic Substances Control Act (TSCA) to burn the waste in an incinerator that meets TSCA design and operating standards.

The lead and support agencies (typically EPA and the state) are responsible for the identification of ARARs and will work closely with other federal and/or state agencies to obtain information or technical assistance. ARARs are identified on a site-by-site basis. Features such as the chemicals present, the location, the physical features, and the actions being considered as remedies at a given site will determine which standards must be heeded.

For remedial actions, CERCLA requires compliance with ARARs for all hazardous substances remaining on-site at the end of the response. Removal actions must attain ARARs to the extent practicable, considering site-specific circumstances, including the urgency of the situation, the scope of the removal action, and the impact of ARARs on the cost and duration of the removal action.

In addition to CERCLA 321, see 40 CFR 300 Subpart E, Hazardous Substance Response, for further mention of ARARs.