Current through Register Vol. 48, No. 38, September 20, 2024
The Stage 2 site investigation must be designed to complete
the identification of the extent of soil and groundwater contamination at the
site that, as a result of the release, exceeds the most stringent Tier 1
remediation objectives of 35 Ill. Adm. Code 742 for the applicable indicator
contaminants. The investigation of any off-site contamination must be conducted
as part of the Stage 3 site investigation.
a) The Stage 2 site investigation must
consist of the following:
1) The additional
drilling of soil borings and collection of soil samples necessary to identify
the extent of soil contamination at the site that exceeds the most stringent
Tier 1 remediation objectives of 35 Ill. Adm. Code 742 for the applicable
indicator contaminants. Soil samples must be collected in appropriate locations
and at appropriate depths, based upon the results of the soil sampling and
other investigation activities conducted to date, provided, however, that soil
samples must not be collected below the groundwater table. All samples must be
analyzed for the applicable indicator contaminants; and
2) The additional installation of groundwater
monitoring wells and collection of groundwater samples necessary to identify
the extent of groundwater contamination at the site that exceeds the most
stringent Tier 1 remediation objectives of 35 Ill. Adm. Code 742 for the
applicable indicator contaminants. If soil samples are collected from a
monitoring well boring, the samples must be collected in appropriate locations
and at appropriate depths, based upon the results of the soil sampling and
other investigation activities conducted to date, provided, however, that soil
samples must not be collected below the groundwater table. All samples must be
analyzed for the applicable indicator contaminants.
b) The Stage 2 site investigation plan must
include, but not be limited to, the following:
1) An executive summary of Stage 1 site
investigation activities and actions proposed in the Stage 2 site investigation
plan to complete the identification of the extent of soil and groundwater
contamination at the site that exceeds the most stringent Tier 1 remediation
objectives of 35 Ill. Adm. Code 742 for the applicable indicator
contaminants;
2) A characterization
of the site and surrounding area, including, but not limited to, the following:
A) The current and projected post-remediation
uses of the site and surrounding properties; and
B) The physical setting of the site and
surrounding area including, but not limited to, features relevant to
environmental, geographic, geologic, hydrologic, hydrogeologic, and topographic
conditions;
3) The
results of the Stage 1 site investigation, including but not limited to the
following:
A) One or more site maps meeting
the requirements of Section
734.440
that show the locations of all borings and groundwater monitoring wells
completed to date, and the groundwater flow direction;
B) One or more site maps meeting the
requirements of Section
734.440
that show the locations of all samples collected to date and analyzed for the
applicable indicator contaminants;
C) One or more site maps meeting the
requirements of Section
734.440
that show the extent of soil and groundwater contamination at the site that
exceeds the most stringent Tier 1 remediation objectives of 35 Ill. Adm. Code
742 for the applicable indicator contaminants;
D) One or more cross-sections of the site
that show the geology of the site and the horizontal and vertical extent of
soil and groundwater contamination at the site that exceeds the most stringent
Tier 1 remediation objectives of 35 Ill. Adm. Code 742 for the applicable
indicator contaminants;
E)
Analytical results, chain of custody forms, and laboratory certifications for
all samples analyzed for the applicable indicator contaminants as part of the
Stage 1 site investigation;
F) One
or more tables comparing the analytical results of the samples collected to
date to the most stringent Tier 1 remediation objectives of 35 Ill. Adm. Code
742 for the applicable indicator contaminants;
G) Water supply well survey documentation
required pursuant to Section
734.445(d)
of this Part for water supply well survey activities conducted as part of the
Stage 1 site investigation; and
H)
For soil borings and groundwater monitoring wells installed as part of the
Stage 1 site investigation, soil boring logs and monitoring well construction
diagrams meeting the requirements of Sections
734.425
and
734.430
of this Part; and
4) A
Stage 2 sampling plan that includes, but is not limited to, the following:
A) A narrative justifying the activities
proposed as part of the Stage 2 site investigation;
B) A map depicting the location of additional
soil borings and groundwater monitoring wells proposed to complete the
identification of the extent of soil and groundwater contamination at the site
that exceeds the most stringent Tier 1 remediation objectives of 35 Ill. Adm.
Code 742 for the applicable indicator contaminants; and
C) The depth and construction details of the
proposed soil borings and groundwater monitoring wells.
c) If the owner or operator
proposes no site investigation activities in the Stage 2 site investigation
plan and none of the applicable indicator contaminants that exceed the most
stringent Tier 1 remediation objectives of 35 Ill. Adm. Code 742 as a result of
the release extend beyond the site's property boundaries, upon submission of
the Stage 2 site investigation plan the owner or operator must cease site
investigation and proceed with the submission of a site investigation
completion report in accordance with Section
734.330
of this Part. If the owner or operator proposes no site investigation
activities in the Stage 2 site investigation plan and applicable indicator
contaminants that exceed the most stringent Tier 1 remediation objectives of 35
Ill. Adm. Code 742 as a result of the release extend beyond the site's property
boundaries, within 30 days after the submission of the Stage 2 site
investigation plan the owner or operator must submit to the Agency for review a
Stage 3 site investigation plan in accordance with Section
734.325
of this Part.
d) If the results of
a Stage 2 site investigation indicate that none of the applicable indicator
contaminants that exceed the most stringent Tier 1 remediation objectives of 35
Ill. Adm. Code 742 as a result of the release extend beyond the site's property
boundaries, upon completion of the Stage 2 site investigation the owner or
operator must cease site investigation and proceed with the submission of a
site investigation completion report in accordance with Section
734.330
of this Part. If the results of the Stage 2 site investigation indicate that
applicable indicator contaminants that exceed the most stringent Tier 1
remediation objectives of 35 Ill. Adm. Code 742 as a result of the release
extend beyond the site's property boundaries, within 30 days after the
completion of the Stage 2 site investigation the owner or operator must submit
to the Agency for review a Stage 3 site investigation plan in accordance with
Section
734.325
of this Part.
