before a parcel can be transferred (EPA, 2010b), although groundwater concentrations need not meet drinking water standards prior to transfer. EPA and state regulators must issue a Finding of Suitability for Transfer, providing EPA with authority over federal cleanup at closing military bases and other properties, even if they are not on the NPL (DoD, 1994). There are also provisions for Leasing and Early Transfer, in which non-federal entities may use or take ownership of property before cleanup has been completed (EPA and DoD, 2005; DOE, 1998). In general, this means that regulators must approve of remedies if a transfer is to occur. However, properties that were transferred before the 1986 Superfund Amendments, such as the Defense Department’s Formerly Used Defense Sites and the former Atomic Energy Commission’s Formerly Used Site Remedial Action Program sites, are subject to CERCLA as managed by the Army Corps of Engineers. They are regulated only by the states and territories unless they are placed on the NPL, which gives EPA regulatory oversight as well.
The process outlined above for CERCLA and its counterparts occurs in a straightforward way at only relatively small or simple sites. In reality, the remedial action process is much more complex and nonlinear, particular for the type of sites that are the focus of this study. The process at a particular site can also be more flexible than implied in the description above. The Committee’s combined experience provides the following general observations about how cleanup can deviate from the idealized RCRA and CERCLA models. First, a significant amount of cleanup can be implemented through interim and emergency responses. Second, the study phase is often protracted, for several reasons. And third, at many complex sites attaining drinking water standards throughout the contaminated groundwater zone is difficult and unlikely for many decades, which can complicate the latter stages of remediation.
Interim and Emergency Responses
At most complex sites, actual cleanup activity begins long before the selection of a final remedy. First and foremost, easily accessible source materials can be and are quickly removed, such as piles of drums on the ground surface, leaking lagoons, and surface pits. Sites with surface contamination are typically fenced to prevent easy access. Second, measures are taken to interrupt exposure pathways. For example, in the San Gabriel Valley, California, wellhead treatment was provided to ensure that the public water supply, which derives from contaminated groundwater,