Current through Register Vol. 48, No. 38, September 20, 2024
The comprehensive site investigation is designed to identify
all recognized environmental conditions and all related contaminants of concern
that may be expected to exist at a remediation site. The comprehensive site
investigation shall be performed in two phases as set forth in subsections
740.420(a) and (b).
a) Unless an
alternative is approved by the Agency, the phase I environmental site
assessment shall be designed and implemented in accordance with the procedures
for such assessments set forth in "Standard Practice for Environmental Site
Assessments: Phase I Environmental Site Assessment Process" (ASTM E 1527-00),
incorporated by reference at Section
740.125
of this Part.
b) The phase II
environmental site assessment shall determine the nature, concentration,
direction and rate of movement, and extent of the contaminants of concern at
the remediation site and the significant physical features of the remediation
site and vicinity that may affect contaminant fate and transport and risk to
human health, safety and the environment. At a minimum, the phase II
environmental site assessment shall include:
1) Sampling, analyses, and field screening
measurements indicating the concentrations of contaminants, if any, from the
Target Compound List at Appendix A of this Part and any other contaminants
whose presence has been indicated by the phase I environmental site assessment.
Based on the phase I environmental site assessment, the Agency may add or
delete contaminants from the Target Compound List for sampling, analyses, and
field screening measurements;
2)
Characterization of sources and potential sources of recognized environmental
conditions and the related contaminants of concern, identifying:
A) The sources or potential sources of
contamination;
B) The contaminants
of concern;
C) Statutory or
regulatory classification of the contaminants of concern and contaminated
materials (e.g., hazardous waste, hazardous substance, special
waste);
3)
Characterization of the extent of contaminants of concern, identifying:
A) The actual contaminated medium or
media;
B) The three-dimensional
configuration of contaminants of concern with concentrations delineated;
and
C) The nature, direction, and
rate of movement of the contaminants of concern;
4) Characterization of present and
post-remediation exposure routes, identifying:
A) All natural and man-made pathways that are
on the remediation site, in rights-of-way attached to the remediation site, or
in any areas surrounding the remediation site that may be adversely affected as
a result of a release (from the recognized environmental conditions) and
whether there is evidence of migration of contaminants of concern, in either
solution or vapors, along such pathways that may potentially threaten human or
environmental receptors or that may cause explosions in basements, crawl
spaces, utility conduits, storm or sanitary sewers, vaults or other
spaces;
B) The locations of any
human and environmental receptors and receptor exposure routes; and
C) Current and post-remediation uses of
affected or potentially affected land, groundwater, surface water, and
sensitive habitats; and
5) Characterization of significant physical
features of the remediation site and vicinity that may affect contaminant fate
and transport and risk to human health, safety and the environment.
