Managing Facilities, Due Diligence and Facility Transfers
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NPL, a list of contaminated sites ranked most hazardous by the HRS to
guide the expenditure of cleanup funds. The NPL includes abandoned
and uncontrolled hazardous waste sites, which EPA updates periodically.
The NCP excludes sites already subject to EPA's jurisdiction under
RCRA, where facility operators are required, under their hazardous
waste permits, to prevent and clean up contamination.
EPA lists sites on the NPL based on the quantitative HRS. The HRS
consists of several analytical methodologies for estimating the potential
health risks through any of five potential pathways of exposure:
Ground water.
Surface water.
Air.
Direct contact with materials.
Fire and explosion.
The HRS employs a weighting process to assure that a high risk, via
any one or more of the pathways described above, will tend to produce
a high ranking, and so a high priority for cleanup. Sites which receive
the highest ranking under HRS are placed on the NPL and thus become
eligible to have cleanup activities financed by the Superfund. The NPL
includes abandoned and uncontrolled hazardous waste sites.
What Do Site Evaluation, Remedial Action Selection,
and Cleanup Standards Mean?
The site evaluation and cleanup selection
(or Remedial Investiga-
tion/Feasibility Study) process is referred to as the "RI/FS" process.
Remedial investigation covers site assessment activities, under which lead
agencies evaluate the nature and extent of site contamination and general
site conditions, and begin to identify possible cleanup methods. The
remedial action selected must attain a specified degree of cleanup and
control of further releases which, at a minimum, assure protection of
human health and the environment. EPA establishes the cleanup
standards to impose, taking into account the risk posed to human health
and the environment, as well as "applicable or relevant and appropriate
requirements" (ARARs) for environmental quality found in other
federal, state, and local environmental and health laws. This includes
selection of a remedial action that enables attainment of maximum
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