to the Remedial Investigation process under CERCLA. If it is determined that corrective action is required, the site owner will conduct a corrective measures study. Not unlike the feasibility study in CERCLA, a corrective measures study evaluates and selects the remedy and is conducted by the facility owner with oversight from the EPA or the state.
The RCRA program recommends that corrective action be based on risk (EPA, 1997c). EPA’s RCRA guidance specifies that cleanup levels be set at federal drinking water standards (where they exist) or be based on a residential drinking water exposure scenario where groundwater is currently used or may be reasonably expected to be used as a source of drinking water (EPA, 2004). RCRA regulations define the point of compliance as the “vertical surface located at the hydraulically down gradient limit of the waste management area that extends down to the uppermost aquifer underlying the regulated units” (EPA, 2004), which conceptually is the boundary of the waste disposal or other management area at the RCRA facility. The exact location is determined on a site-by-site basis.
The two primary RCRA milestones include the human exposures environmental indicator and the groundwater environmental indicator (see Chapter 2). The objectives that are frequently called for in site-specific agreements between owners and operators of treatment, storage, and disposal facilities and regulatory authorities are typically defined in terms of concentrations of particular contaminants as measured at the boundaries of given units of real property.
Public participation is a part of the corrective measures selection process, but community acceptance (the ninth NCP criterion) is not a statutory requirement for RCRA sites. While in many cases regulators may have established a robust community involvement process, in general this is less extensive than at sites regulated under CERCLA. For example, there are funding sources, such as Technical Assistance Grants, available for CERCLA public involvement that do not exist for RCRA, and regional Superfund programs have Community Involvement Coordinators.
While RCRA permits do not have a statutory requirement for five-year reviews, periodic reviews may be built into RCRA permits. EPA views RCRA permits as “living documents that can be modified to allow facilities to implement technological improvements, comply with new environmental standards, respond to changing waste streams, and generally improve waste management practices” (EPA, 2011b).
As part of RCRA, UST cleanup is also overseen by state and territories or their subjurisdictions. Of interest for this chapter is that the definition of UST “closure,” which is a major goal of UST programs, varies significantly from state to state. According to the ITRC 2009 report, historic cleanup goals for LNAPLs have been to remove them “to the maximum extent practicable (MEP),” although some states provide no interpretation