The Technical Branch is staffed by the engineers and geologists of the Regulated Storage Tank (RST) Division, and their primary job is providing technical assistance and regulatory oversight for Owner/Operator-lead corrective actions involving underground storage tanks (USTs) and aboveground storage tanks (ASTs) storing petroleum products.

Additionally, the Technical Branch also participates in corrective actions for other sources of environmental petroleum contamination (state-lead responses, transportation accidents, Brownfields, and so forth) under the authority of other Department programs.

ADEQ has delegated authority to oversee corrective action at facilities with USTs regulated under Subtitle I of the Resource Conservation and Recovery Act (RCRA). The federal UST regulation (40 CFR 280) has been adopted by reference in Arkansas, and due to the way the enabling legislation is drafted, the RST Division=s corrective action program must be implemented within the framework of Subpart F (40 CFR 280.60). Some perspective on the process may be gained from the simple graphic below:

RST Flowchart

The process is managed as a straightforward regulatory compliance/enforcement program, for regulated facilities only. When work is ordered by the Technical Branch staff, it is requested with the expectation that it will be delivered within a specified time period, and will be conducted and reported in a manner which demonstrates its technical adequacy.

There are no provisions for voluntary clean-up within the RST Division corrective action program. Under certain circumstances, a voluntary clean-up may be over-sighted by the Hazardous Waste Division through the Arkansas Brownfields program. Visit the Brownfields website at http://www.adeq.state.ar.us/hazwaste/branch_programs/brownfields.htm for more information.

Initial Response to a Release

Regulatory guidance for initial response and abatement activities is found in 40 CFR 280.61 and 280.62. Briefly, upon confirmation of a release, the responsible party must:

Report the release to the implementing agency within 24 hours of discovery (e.g. by telephone or e-mail).
Take immediate action to prevent any further release of the regulated substance to the environment.
Identify and mitigate fire, explosion, and vapor hazards.
Remedy hazards posed by contaminated soils or other wastes resulting from release confirmation, site investigation, hazard abatement, or corrective action activities.

While the regulatory citation applies only to USTs, these steps may also be required in the event of a release from a leaking AST, as well, if the corrective action is under the oversight of the RST Division.

Pre-approval of costs for initial response activities is not required for Trust Fund participation. The costs incurred, however, must be reasonable if they are to be allowed for reimbursement. An emergency should not be used as an excuse for failure to exercise common sense and prudence where costs are concerned.

Free Product Recovery

Free product is defined in 40 CFR 280.12 as “a regulated substance that is present as a non-aqueous phase liquid [e.g. liquid not dissolved in water],” sometimes also called NAPL.

Until fairly recently, the position of ADEQ on free product was that its presence constituted an environmental emergency, requiring immediate attempts at recovery. Finding free product in a monitoring well carries a large psychological impact, and expedited recovery attempts made everyone involved feel that something worthwhile was being accomplished.

Unfortunately, it is impossible to correlate an observed thickness of product in a monitoring well with risk to human health and the environment. Further, experience over the last decade has shown that even aggressive and effective product recovery does not significantly influence the environmental outcome for the release site, and as a result, interim (that is, before the release is fully investigated/assessed) product recovery as a risk management tool has been de-emphasized.

There are still circumstances where interim measures to recover free product may be desirable. If sufficient product thicknesses are present on the groundwater table, the product itself may be mobile. Under these conditions, interim measures are also likely to be cost-effective, and ADEQ may ask that some type of monitoring/recovery program be implemented. Otherwise, recovery will be addressed after the released has been fully investigated, as a part of the overall Corrective Action Plan for the site.

Guidance for investigating the presence of free product and implementing effective recovery measures is available from USEPA in a document entitled "How to Effectively Recover Free Product at Leaking Underground Storage Tank Sites - A Guide for State Regulators." This document can be downloaded from http://epa.gov/OUST/pubs/fprg.htm.

Initial Site Characterization

Unless otherwise directed by ADEQ, an Initial Site Characterization (ISC) must be reported within 45 days of a confirmed release. This regulatory requirement and a description of compliance are found in 40 CFR 280.63.

It is clear from a reading of the Preamble to Part 280 (53 FR 37177) that USEPA intended the ISC to be the decision point for the corrective action program between those facilities which do not require further work, and those facilities which have suffered an environmentally-significant release, for which further investigation and/or remediation is necessary.

In order for ADEQ to make this determination, three major questions must be answered by the ISC: Have wells (including monitoring wells) or other receptors been impacted by the release? Is free product present in or on the uppermost groundwater unit beneath the site? Are nearby receptors potentially impacted by the release?

In addition to supporting ADEQ decision-making, the ISC provides important prerequisite information for the owner/operator to design the next level of investigation. This is the most common problem area for ISC reports. It is easily possible for enough information to be presented for ADEQ to determine further investigation is necessary, and still not have enough information to adequately devise and cost the investigation.

Because of the short time period allowed for compliance, pre-approval of costs for the Initial Site Characterization is not required for Trust Fund participation. The costs incurred, however, must be reasonable and necessary if they are to be allowed for reimbursement. While the regulatory citation applies only to USTs, an Initial Site Characterization may be required in the event of a release from other regulated units as well, if the response is under the oversight of the RST Division.

Investigation for Soil and Groundwater Clean-up

If review of the Initial Site Characterization results in the determination by ADEQ that an environmentally-significant release has occurred, an investigation to identify the location of soils impacted by the release and the level and extent of dissolved product contamination in groundwater will be requested. This regulatory requirement and a description of compliance are found in 40 CFR 280.65.

The work described by this citation is complex, and must be performed and reported by persons qualified by training and experience, in a manner which demonstrates its technical adequacy. It falls under Arkansas professional practice statutes which have been interpreted to require the services of a Professional Engineer or Geologist licensed to practice in Arkansas to seal site assessment reports (Memo From AR Board for Prof.Geologists on Geologic Interpotation And Analysis).

While the regulatory citation applies only to USTs, an Investigation for Soil and Groundwater Clean-up may be required in the event of a release from other regulated units as well, if the response is under the oversight of the RST Division.

Risk-based Corrective Action (RBCA)

Beyond the non-degradation legislation which chartered the Department, Arkansas does not have a specific groundwater quality law or regulation. Consequently, each program dealing with groundwater has generic corrective action goals which are rooted in the federal law or regulation from which the program is delegated. For the RST Division, there are two program goals:

Protection of human health and the environment from regulated substance exposures (40 CFR 280.66); and
Source control “to the maximum extent practicable” to prevent the spread of regulated substance contamination (40 CFR 280.64).

Each release response will be managed on a site-specific basis, within the two program goals outlined above. When sufficient site and risk investigation data becomes available, the Technical Branch staff will draft an Exposure Assessment which will summarize what is known about the release, identify pertinent exposures, and establish preliminary remediation goals. A Corrective Action Plan will then be ordered, if remediation is justified.

Goals to address human health exposures will be established using the ASTM E1739-95 standard. Points of compliance will be assigned by ADEQ based on the relationship to the impacted receptors.
For ecological exposures, the National Ambient Water Quality Criteria will be used for groundwater underflow to waters of the state. Points of compliance will be assigned by ADEQ based on the relationship to the impacted receptors.
For groundwater contamination source controls, a groundwater goal equal to the NAPL equilibrium concentration and incorporating a Dilution Attenuation Factor of ten (10) to account for sampling uncertainties will be specified. Points of compliance will be throughout the contaminated zone.

Petroleum products (as defined in 40 CFR 280.12) consist of a large and varying number of individual constituents, and it would not be practical to analyze for all of them. A suggested listing the indicators used for assessing petroleum releases in Arkansas is found below:

Benzene	Acenaphthene
Toluene	Anthracene
Ethyl-benzene	Benzo (a) anthracene
Mixed Xylenes	Benzo (a) pyrene
Methyl-t-Butyl-Ether	Benzo (b) fluoranthene
1,2-Dibromoethane	Benzo (k) fluoranthene
1,2-Dichloroethane	Chrysene
Naphthalene	Dibenzo (a,h) anthracene
Arsenic	Fluoranthene
Cadmium	Fluorene
Chromium	Ideno (1,2,3-cd) pyrene
Lead	Pyrene
Volatile Petroleum Hydrocarbons (for source control only)
Extractable Petroleum Hydrocarbons (for source control only)

These indicator parameters have been chosen because of their toxicity, potential for migration (solubility, persistence), relative ease of analysis, and because they are most often present in soil and groundwater contamination scenarios involving petroleum products.

No reference methods are specified. Any analytical method which is capable of meeting the necessary quantitation levels is acceptable for compliance purposes.

Site Assessment Report (SAR)

As a part of the corrective action process, the Division staff may, after review of the Initial Site Characterization and the circumstances of the release, request further assessment of the site for the purposes of defining the risk or establishing the design of a remediation program. Authority to request further assessment and regulatory guidance for investigations for soil and groundwater clean-up is found in 40 CFR 280.65.

The Site Assessment Report will be requested in writing by the Department, according to the conditions of 280.65.
Specific guidance regarding the goals of the investigation, the content and format of the report, and the schedule for compliance will be provided at the time the SAR is requested.
To ensure that the goals are met and that the investigation methods are appropriate to the site, a work plan will be reviewed and approved by the technical staff before the work is undertaken.
To ensure that the costs for the SAR will be eligible for reimbursement from the Trust Fund, the work plan must include estimated unit costs, and approval will be granted for the costs by the Trust Fund Administrator before the work is undertaken.

The work described by this section is demanding and must be performed and reported by persons with specific education and experience, in a manner which demonstrates technical competency. It falls under professional practice statutes which have been interpreted to require the services of a Professional Geologist licensed to practice in Arkansas to seal site assessment reports.

While the regulatory citation applies only to USTs, the SAR may also be required in the event of a release from a leaking aboveground storage tank as well, if it is under the oversight of the RST Division.

Corrective Action Plans

At any time during the corrective action process, the RST Division staff may devise (or cause to be devised) a plan for responding to soil and groundwater contamination, or other attenuation of public health or welfare hazards. The authority to request Corrective Action Plans and regulatory guidance for their development and implementation is found in 40 CFR 280.66.

All Corrective Action Plans must address the following elements in detail:

A discussion of the background of the case, including a chronology of the events leading up to the development of the Corrective Action Plan. Information must be provided about how the release was detected, the nature and estimated quantity of the released regulated substance(s), and a summary of response actions taken to date.

A Conceptual Site Model to summarize what is known about the geology and hydrogeology of the site, physical site conditions, contaminant sources and distributions, exposure pathways and migration routes, and impacted or potentially-impacted receptors.

A coherent strategy for adequately protecting human health, safety, and the environment, with objective, media-specific goals and points of compliance for each goal.

A listing of the actions (tasks) required to meet the goals of the Corrective Action Plan, including any contingency actions, and a proposed schedule for their accomplishment.

If the facility is eligible to participate in the Arkansas Petroleum Storage Tank Trust Fund, an estimate of the costs for each task must be included.

A program for monitoring, evaluating, and reporting progress toward meeting the goals of the Corrective Action Plan.

A plan for notifying stakeholders of the existence of the Corrective Action Plan, according to the provisions of 40 CFR 280.67. Specific notice and a copy of the Corrective Action Plan must be provided to those stakeholders directly impacted, and general notice must be provided to the public in the area of the release.

While the regulatory citation applies only to USTs, a Corrective Action Plan my be required in the event of a release from other regulated units as well, if the response is under the oversight of the RST Division.

Aboveground Storage Tanks (ASTs)

Corrective actions for certain sizes and types of aboveground storage tanks (ASTs) are also under the oversight of the RST Division, and may be eligible for State Petroleum Storage Tank Trust Fund participation. These tanks are defined as holding liquid petroleum motor fuels, and ranging in size from 1,320 to 40,000 US gallons in capacity.

USEPA’s Oil Pollution Prevention regulation (40 CFR 112) was first published in the Federal Register on 12/11/73, and received an extensive update on 8/16/02. This regulation provides the technical standards for aboveground product storage and operations, and requires spill prevention control and countermeasures (SPCC) plans for each facility. This program is not delegated in Arkansas, and all questions about installation, operation, and SPCC plans should be directed to USEPA – Region VI at 214-666-2200.

Any corrective action required by Part 112, however, is to be conducted under the enforcement authority of the Clean Water Act. That program is delegated in Arkansas, and by order of the Director, oversight of any release response required will be provided by the RST Division, according to the policies and procedures established by the Division.

Due to staff and contractor familiarity with the corrective action process found in Part 280, that model will be used for all AST corrective actions, including the requirement for public participation. Trust Fund participation, if the AST is eligible, will likewise be on the same basis as for a UST release.