Indiana Administrative Code
Title 329 - SOLID WASTE MANAGEMENT DIVISION
Article 9 - UNDERGROUND STORAGE TANKS
Rule 6 - Closure
Section 6-2.6 - Site assessment sampling requirements
Universal Citation: 329 IN Admin Code 6-2.6
Current through September 18, 2024
Authority: IC 13-14-8; IC 13-23-1
Affected: IC 13-12-3-2
Sec. 2.6.
(a) Soil sampling for an in-place closure must be conducted as follows:
(1) To request conditional approval for
in-place closure, the owner and operator shall submit a site plan with an
accompanying map showing proposed boring locations to the department and to the
office of the state fire marshal, using the form described in
329 IAC 9-2-2(f)
as follows:
(A) The map must be to scale and include the
entire site.
(B) An additional map
showing only the underground storage area must be included for sites larger
than one (1) acre.
(C) The proposed
boring locations must be as follows:
(i) One
(1) boring every twenty (20) feet around the tank area, with a minimum of four
(4) borings.
(ii) Each boring must
be within three (3) feet adjacent to the UST.
(2) The commissioner may grant conditional
approval to proceed with in-place closure of the UST system based on the
following:
(A) The location of the borings
identified under subdivision (1).
(B) Approval from the office of the state
fire marshal.
(3) After
approval is received under subdivision (2), the owner and operator may proceed
with soil borings that must meet the following requirements:
(A) Soil sampling must be performed
continuously using a sampling device relevant to the drilling technology
used.
(B) Borings must extend two
(2) feet or greater below the elevation of the base of the UST.
(C) If the boring depth is fifteen (15) feet
or less, a minimum of two (2) soil samples are required at the point where a
contaminant is detected, one (1) each from the:
(i) midpoint of the boring; and
(ii) bottom of the boring.
(D) If the boring depth is greater
than fifteen (15) feet, a minimum of three (3) soil samples are required as
follows:
(i) The most shallow soil sample must
be taken one (1) foot or greater below grade.
(ii) Samples must be taken where the release
is suspected or detected.
(b) Soil sampling for removal closure must be conducted as follows:
(1) Native soil samples
must be taken from the following areas:
(A)
Tank cavity excavation.
(B) Piping
trenches.
(C) Dispensing unit
areas.
(D) Remote fill pipe
trenches.
(2) Each UST
excavation must be sampled separately. Composite samples are not acceptable for
removal closure. The samples must meet the following requirements:
(A) All samples must be discrete grab samples
taken directly from the undisturbed native soil from the base and sidewalls of
the excavation. Excavated materials must be staged in a separate area. The
following requirements apply to samples:
(i)
Bottom samples must meet the following requirements:
(AA) Soil sampling must consist of a minimum
of two (2) soil samples taken within two (2) feet below both ends of each
UST.
(BB) If the UST capacity is
greater than ten thousand (10,000) gallons, one (1) additional sample must be
taken within two (2) feet below the middle of the UST.
(ii) Sidewall samples must meet the
following requirements:
(AA) The sidewalls
must be sampled and analyzed at a rate of one (1) sample every twenty (20) feet
of perimeter distance around the excavation zone.
(BB) If the perimeter dimension measures less
than eighty (80) feet, a minimum of one (1) sample for each sidewall must be
taken.
(CC) Sidewall samples must
be taken at a point half the distance from the surface to the bottom of the UST
excavation.
(B) Samples must be discrete grab samples
taken directly from the excavated materials.
(C) Sampling of the excavated soil must occur
for every fifty (50) cubic yards of material.
(3) Native soil under piping and dispenser
islands that routinely contained regulated substances must be sampled. All
samples must be discrete grab samples. The following requirements apply to the
number and location of sampling for piping and dispensers:
(A) Soil sampling from under the piping must
be completed as follows:
(i) The soil must be
sampled every twenty (20) feet, or fraction thereof, along the piping run. If
the piping run is less than twenty (20) feet in length, one (1) sample must be
taken at half the distance between the UST excavation and the pump or dispenser
island.
(ii) Soil must be sampled
from under the piping elbows and connectors.
(B) Soils under the dispenser islands must be
sampled and analyzed at a rate of one (1) soil sample per dispenser.
(C) If the UST system has a remote fill line,
the following soil samples must be collected:
(i) Soils under the remote fill line must be
sampled and analyzed at the origin or fill area and every twenty (20) feet, or
fraction thereof, from the fill area to the UST connection.
(ii) If the remote fill line is less than
twenty (20) feet, one (1) soil sample must be taken half the distance between
the fill area and the UST.
(D) Composite samples are not acceptable for
permanent closure.
(4)
Soil sampling under the piping and product dispenser islands is not required if
all dispensers and piping that routinely contain product are located directly
above the UST system that is being permanently closed by removal and the
location is documented.
(5) During
removal closure, native soil and backfill that is to be returned to the UST
excavation must be sampled. The sampling must meet the following requirements:
(A) The exposure criteria in accordance with
IC 13-12-3-2.
(B) One (1) discrete
grab sample must be taken for every fifty (50) cubic yards of native soil or
backfill.
(c) Soil samples for a change-in-service must be taken as follows:
(1) Soil sampling must be performed
continuously using a sampling device relevant to the drilling technology and
used every twenty (20) feet around the tank area, with a minimum of four (4)
borings as follows:
(A) Each soil boring
must:
(i) be within three (3) feet of the
UST; and
(ii) extend two (2) feet
or greater below the elevation of the base of the UST.
(B) If the soil boring depth is fifteen (15)
feet or less:
(i) two (2) soil samples must
be taken where a contaminant is detected;
(ii) one (1) soil sample must be taken at the
midpoint of the soil boring; and
(iii) one (1) soil sample must be taken at
the bottom of the soil boring.
(C) If the soil boring depth is greater than
fifteen (15) feet, three (3) soil samples are required as follows:
(i) Samples must be collected where the
release is suspected or detected.
(ii) One (1) soil sample must be taken one
(1) foot or greater below grade and must be the most shallow sample
taken.
(2)
Piping and dispenser sampling and analysis must be completed in accordance with
subsection (b)(3) and (b)(4).
(d) Water samples for a permanent closure or change-in-service must be collected as follows:
(1) For a permanent closure or
change-in-service, a ground water sample must be collected within an area where
a suspected contaminant release has occurred, or where a chemical of concern
release has been substantiated through one (1) of the following:
(A) Visual staining of the soil or
water.
(B) Field screening with one
(1) of the following:
(i) Flame ionization
detector.
(ii) Photo ionization
detector.
(iii) Field gas
chromatograph.
(C)
Petroleum odors.
(D) Laboratory
analytical results.
(2)
For an in-place closure or change-in-service, borings and water sampling are to
be made as follows:
(A) One (1) boring must
be placed in each of the four (4) principal directions within ten (10) feet of
the area most likely to have contaminated ground water.
(B) Each boring must extend to the first
saturated ground water zone or to a total depth of thirty (30) feet below grade
at the area of suspected or confirmed release. A water sample must be collected
from each boring if ground water is present within a depth of thirty (30) feet
or less.
(C) If ground water is not
encountered within a depth of thirty (30) feet, an additional soil sample must
be obtained at the base of the boring or a minimum depth of thirty (30)
feet.
(3) For removal
closure, water sampling must be conducted as follows:
(A) If water is encountered in an excavation,
a minimum of one (1) water sample must be collected from the water
encountered.
(B) The ground water
sample collected in subdivision (1) must be collected from a continuously
sampled boring that extends to the first saturated ground water zone or to a
total depth of thirty (30) feet below grade at the area of suspected or
confirmed release.
(C) If ground
water is not encountered within a depth of thirty (30) feet, a soil sample must
be obtained at the base of the boring.
(4) If bedrock is encountered in a boring
before a depth of thirty (30) feet is reached, and a saturated ground water
zone is not encountered in the boring, an owner or operator may contact the
department for approval of alternative sampling or waiver of ground water
sampling requirements. The department may approve a waiver of ground water
sampling within the bedrock if the owner or operator can demonstrate the
following:
(A) A soil zone at least ten (10)
feet thick existing immediately above the bedrock does not have a
contaminant.
(B) A soil sample
collected immediately above the bedrock does not have a contaminant.
(e) The following conditions apply to a waiver of sampling:
(1)
The commissioner may waive sampling under any of the following conditions:
(A) A leaking underground storage tank
incident number is assigned and the following requirements are completed:
(i) Permanent closure is conducted in
response to a confirmed release at the site.
(ii) The confirmed release occurred before
the request for permanent closure.
(B) The initial site characterization meets
the requirements of 40 CFR
280.63 *.
(C) The corrective action plan meets the
requirements of 40 CFR
280.66 *.
(D) Bedrock was encountered during the boring
as described in subsection (d)(4).
(2) Sites that have previous releases and are
not under remediation at the time of permanent closure are not eligible for a
sampling waiver.
(3) In-place
closure sampling requirements may not be waived.
*These documents are incorporated by reference. Copies may be obtained from the Government Publishing Office, www.gpo.gov, or are available for review at the Indiana Department of Environmental Management, Office of Legal Counsel, Indiana Government Center North, 100 North Senate Avenue, Thirteenth Floor, Indianapolis, IN 46204.
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