BUSTR UST Closure Sampling - Assessment Requirements and Procedures

Overview

When an underground storage tank (UST) system in Ohio is permanently removed, closed in place, changed in service, or has been out of service for more than 12 months without a permit, a closure assessment is required under OAC 1301:7-9-12. The closure assessment determines whether petroleum has been released from the UST system into the surrounding soil and groundwater.

This guide covers the sampling requirements for permanent removals - the most common closure scenario. The requirements are defined in the BUSTR Technical Guidance Manual (TGM) Chapter 2 and apply to all BUSTR-regulated petroleum UST systems in Ohio.

A typical closure involves an abandoned gas station, fuel depot, or other facility with one or more USTs. The tanks, piping, and dispensers are excavated and removed. Soil samples are collected from the excavation, field screened, and selectively submitted to a laboratory for analysis. If results are below action levels, BUSTR issues a No Further Action (NFA) letter. If results exceed action levels, the owner/operator must report a confirmed release to BUSTR within 24 hours and enter the corrective action process.

Before You Start

Permitting

A BUSTR permit must be obtained before any removal work begins. Permits are issued by the State Fire Marshal’s Bureau of Testing and Registration (614-752-7126) or the local fire department with delegated authority. Filing the permit application satisfies the notification requirement under OAC 1301:7-9-12.

Required On-Site Personnel

Two certified individuals must be present during removal:

Certified UST Installer - directs all removal activities and controls personnel performing work on the UST system
Certified UST Inspector (CUSTI) - documents that fire and explosion hazards are properly handled. May be a BUSTR inspector, delegated authority inspector, or private CUSTI.

Neither the installer nor the inspector determines whether petroleum contamination exists. That is the environmental consultant’s role.

Site Characterization

Before sampling, document the site history and conduct a visual evaluation:

Historical and current land use of the site and surrounding properties
Previous closures, releases, and suspected releases
Date the UST system was last used and by whom
Locations of current and former UST systems (sometimes there are more tanks than expected - abandoned systems from previous owners are common at older gas stations)
Evidence of past operational problems: surface staining, concrete patches, areas where piping or pump islands appear to have existed

What Gets Removed

For a permanent removal, all of the following must be excavated:

All USTs
All product piping (lines that routinely contain regulated substances)
All dispensing units
All associated backfill from the tank cavity, piping trenches, and dispenser areas

Remove no more than one foot of native soil from the sidewalls and bottom of the excavation. The excavated backfill is assumed to be petroleum contaminated soil (PCS) and must be handled according to OAC 1301:7-9-16 and 17.

Do not over-excavate known contamination without prior approval from the State Fire Marshal. Conducting over-excavation for the purpose of removing contaminated soil will likely require a Tier 1 Source Investigation.

Sample Locations

All field screening samples must be collected within 24 hours of completing the excavation. Samples must be biased toward areas of greatest suspected contamination.

Tank Cavity

Both ends of each UST - collect a sample from the native soil beneath each end of the tank
If a tank is longer than 35 feet, collect an additional sample under the middle of the tank
Sidewalls of the tank cavity - collect samples at a ratio of one sample per 100 square feet of sidewall area, biased toward areas with the highest contamination

Sidewall calculation example: An excavation that is 24 ft wide, 36 ft long, and 13 ft deep has a total sidewall area of 2 x (24 x 13) + 2 x (36 x 13) = 624 + 936 = 1,560 sq ft. This requires 16 field screening samples from the sidewalls (1,560 / 100 = 15.6, rounded up to 16). Divide the sidewall perimeter into 16 equal sections and collect one sample from each.

If groundwater recharges into the excavation, sidewall samples are still required, but recalculate the number based on the surface area of soil above the water table.

Piping Runs

Collect one sample every 10 feet along piping runs that routinely contain regulated substances
Collect samples under joints and connections
Exception: if a joint sample location is within 2 linear feet of another required sample, the duplicate location can be skipped

Dispensers

Collect a sample below each dispensing unit where joints, elbows, and flex connectors are located
Exception: if a dispenser is located directly above a tank being removed, no separate dispenser sample is needed (the tank cavity samples cover that area)

Remote Fill Pipes

Collect a sample below any remote fill pipe area that is more than 10 feet from the UST cavity

Groundwater

Evacuate any water encountered in the excavation
If water recharges into the excavation within 24 hours of pumping, a groundwater sample must be collected
Collect groundwater samples from any dispenser area, piping trench, or tank cavity that contains groundwater
If no water recharges within 24 hours, only soil sampling is required

Field Screening

All samples collected from the locations above must be field screened. Field screening is used to determine which samples are submitted to the laboratory - you do not send every sample to the lab.

Field screen samples using a photoionization detector (PID) or flame ionization detector (FID) following the procedures in Appendix A of the TGM. Record the field screening reading for every sample collected. The highest readings guide which samples go to the lab.

If field screening is not conducted, all samples must be submitted to the laboratory. This is significantly more expensive, so field screening is strongly recommended.

If no field screening readings are detected at any location, the samples submitted to the lab should be biased toward the areas of greatest suspected contamination.

Which Samples Go to the Lab

The TGM specifies minimum laboratory submission requirements based on the number of samples collected and their field screening results:

Tank Cavity Samples

Submit the two samples with the highest field screening readings from each tank cavity per set of three tanks or fraction thereof.

1, 2, or 3 tanks in one cavity: submit 2 samples
4, 5, or 6 tanks in one cavity: submit 3 samples

Sidewall samples are included in this selection - if a sidewall sample has the highest reading, it gets submitted.

Piping Samples

Submit one sample for every five piping samples collected (or fraction thereof). At minimum, one sample from each distinct piping run leading to a separate dispensing area or remote fill must be submitted, even if this exceeds the 1-in-5 ratio.

How to select piping samples:

Identify each separate dispensing area (typically a single dispenser or group of dispensers under one canopy)
Submit the highest field-screened piping sample from each dispensing area
Fill remaining submission slots with the next-highest readings from all piping samples combined

Example: A site has two dispensing areas - a gasoline area with 90 ft of piping (9 samples) and a kerosene area with 25 ft of piping (2 samples). Total: 11 piping samples collected, so 3 must be submitted (11/5 = 2.2, rounded up to 3). Sample 1: highest reading from kerosene area piping. Sample 2: highest reading from gasoline area piping. Sample 3: next highest reading from any piping sample site-wide.

Dispenser Samples

Submit one sample from each dispenser island - the sample with the highest field screening reading. If a dispenser island has more than three dispensing units, submit one additional sample for each group of three (or fraction thereof).

Remote Fill Samples

Submit one sample from each remote fill area more than 10 feet from the UST cavity.

Water Samples

Submit all groundwater samples collected from the excavation.

Stockpile Samples

Excavated soil is assumed to be PCS. Stockpile sampling requirements depend on the volume of material generated (TGM Table 2.1):

Stockpile Volume	Min. Grab Samples for Field Screening	Min. Samples to Lab
Less than 25 cubic yards	3	2
26-100 cubic yards	6	3
101-250 cubic yards	12	6
251-450 cubic yards	18	8
More than 450 cubic yards	18 plus 1 per additional 50 cy	8 plus 1 per additional 100 cy

If samples are not field screened, all grab samples must be submitted for laboratory analysis.

Analytical Groups and Chemicals of Concern

The chemicals analyzed depend on what product was stored in the UST system. The TGM defines five analytical groups (Table 2.2):

Analytical Group 1 - Light Distillates

Gasoline (unleaded, leaded), naphtha, gasoline blended with alcohol, racing fuel, aviation gasoline.

COCs: Benzene, toluene, ethylbenzene, o/m/p-xylenes, naphthalene, 1,2,4-trimethylbenzene, MTBE, 8 PAHs (benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, dibenz(a,h)anthracene, indeno(1,2,3-cd)pyrene, naphthalene), TPH C6-C12.

Additional for pre-1996 gasoline USTs: EDB (1,2-dibromoethane) and EDC (1,2-dichloroethane) - these lead scavengers must be analyzed for automotive gasoline USTs in service before January 1, 1996. Not required for USTs installed on or after that date.

EDB and EDC are always required for aviation gasoline, racing fuel, and used oil USTs regardless of installation date.

Analytical Group 2 - Middle Distillates

Diesel, light fuel oils, Stoddard solvents, mineral spirits, kerosene, biodiesel blended with diesel, jet fuels.

COCs: Benzene, toluene, ethylbenzene, xylenes, naphthalene, 1,2,4-trimethylbenzene, MTBE, 8 PAHs, TPH C10-C20.

Note on mixed sites: If a release contains both Group 1 and Group 2 COCs (for example, a facility that stored both gasoline and diesel), naphthalene must be analyzed for both the volatile and semi-volatile organic range. Report the highest concentration of the two.

Analytical Group 3 - Heavy Petroleum Distillates

Lubricating and hydraulic oils.

COCs: Benzene, naphthalene, 8 PAHs, chlorinated hydrocarbons (VOCs), TPH C10-C20, TPH C20-C34.

Analytical Group 4 - Used Oil

COCs: Benzene, naphthalene, MTBE, EDB, EDC, 8 PAHs, chlorinated hydrocarbons (VOCs), TPH C6-C12, TPH C10-C20, TPH C20-C34.

Used oil USTs contain both petroleum and potentially hazardous substances. They are regulated by BUSTR for both closure and corrective action.

Analytical Group 5 - Unknown or Other

If the contents of the UST are unknown or do not fit into Groups 1-4, contact BUSTR to determine the appropriate COCs and analytical methods before sampling. COCs may be selected based on SDS information for the stored chemical.

Analytical Methods

Common methods referenced in TGM Table 2.2:

Soil VOCs (BTEX, MTBE, TMB): SW-846 Methods 8021 or 8260
Soil SVOCs (PAHs): SW-846 Methods 8270 or 8310
Soil TPH: SW-846 Method 8015
EDB/EDC: SW-846 Method 8011
Groundwater VOCs: SW-846 Methods 8021 or 8260
Groundwater SVOCs: SW-846 Methods 8270 or 8310

All samples must be analyzed on a dry-weight basis for soil. All laboratories must be accredited by Ohio EPA, the VAP program, NELAP, or another agency recognized by the State Fire Marshal.

Closure Action Levels

The closure action levels for soil (by soil class) and drinking water are published on our BUSTR closure action levels standards page, sourced from the BUSTR TGM. The default assumptions for closure are:

Residential land use
Groundwater is a drinking water source
Depth to groundwater is less than 15 feet
Soil type is Class 1 unless geotechnical documentation demonstrates otherwise

Bedrock is included in the category of Class 1 soil. Class 1 soils (fine-grained, low permeability) have the lowest action levels. If the site has coarser soils, geotechnical analysis can justify Class 2 or Class 3 classification, which have higher action levels.

For chemicals not listed in the closure action levels table (common with Analytical Groups 3, 4, and 5), action levels can be derived from the BUSTR Spreadsheets or developed using the methodologies in OAC 1301:7-9-13. Physical, chemical, and toxicological properties may be obtained from CIDARS.

TPH analysis is not required for groundwater samples.

What Happens After Sampling

All Results Below Action Levels

If all COC concentrations at every location are below the applicable action levels and the closure assessment form is technically accurate and complete, BUSTR issues an NFA letter. No further action is required.

Any Result Exceeds Action Levels

If any COC at any location exceeds an action level, the owner/operator must:

Report a confirmed release to BUSTR within 24 hours of receiving analytical results
Conduct corrective action as described in OAC 1301:7-9-13 (Chapter 3 of the TGM)
The site enters the tiered corrective action process (Tier 1 Source Investigation, potentially Tier 2 and Tier 3 evaluations)

Closure Assessment Report

The Closure Assessment Form 2022 must be submitted to BUSTR by the owner/operator within 90 days of sample collection. Although consultants typically prepare the report, BUSTR holds the owner/operator responsible for its accuracy, completeness, and timely submission. The owner/operator must sign, date, and submit the form.

The report must include site characterization data, sample locations and depths, field screening results, laboratory analytical data, chain of custody documentation, and the disposition of any regulated liquids and excavated soil.

Practical Field Notes

Expect surprises. Older gas station sites frequently have more tanks than documented. Previous owners may have installed tanks that were never registered. If you encounter an unexpected tank during excavation, it must be addressed under the same closure requirements.

Soil classification matters. Class 1 soil (fine-grained, low permeability) has the lowest action levels. If the site has sandy or gravelly soils, you may be able to justify Class 2 or 3 classification with geotechnical analysis, which gives you higher action levels. But the default assumption is Class 1 unless you prove otherwise.

Groundwater complicates everything. If groundwater recharges into the excavation, you need water samples in addition to soil samples. Water samples have lower thresholds (ppb vs. ppm for soil) and all water samples must be submitted to the lab - there is no field screening reduction for groundwater.

The 24-hour clock is real. You have 24 hours from completing the excavation to collect all field screening samples. Plan your sampling day around the excavation timeline - if the excavation finishes at 3pm, you need all samples collected by 3pm the next day.

Stockpile management. All excavated backfill is assumed to be PCS until proven otherwise. It must be stored and disposed of according to the PCS rules. If soil is shipped directly to a licensed disposal facility, it must be sampled to the extent required by the receiving facility before shipment.

Source

BUSTR Technical Guidance Manual (TGM) 2022, Chapter 2: UST Closure Requirements. OAC 1301:7-9-12. BUSTR TGM Table 2.1: Stockpile Sampling. BUSTR TGM Table 2.2: Chemicals of Concern. BUSTR TGM Table 2.3: Summary of Closure Action Levels.