329 Ind. Admin. Code 9-6-2.6

Current through October 23, 2024

Section 329 IAC 9-6-2.6 - Site assessment sampling requirements

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.

329 IAC 9-6-2.6

Solid Waste Management Division; 329 IAC 9-6-2.6; filed 5/29/2018, 3:35 p.m.: 20180627-IR-329160204FRA

Filed 9/12/2023, 4:27 p.m.: 20231011-IR-329200025FRA