Code of Maine Rules
06 - DEPARTMENT OF ENVIRONMENTAL PROTECTION
096 - DEPARTMENT OF ENVIRONMENTAL PROTECTION - GENERAL
Chapter 691 - RULE FOR UNDERGROUND OIL STORAGE FACILITIES
Appendix 096-691-P - Requirements for a Site Assessment at Facility Closure or Tank Abandonment

Current through 2024-13, March 27, 2024

1. The purpose of a site assessment for facility closure or abandonment is to determine if discharges of oil have occurred requiring notification of the Commissioner and corrective action by the owner, operator or another responsible party.

2. General requirements

A. A site assessment meeting all the requirements of this appendix must be completed prior to the completion of facility closure or the abandonment of any portion of a facility in accordance with section 11. This includes abandonment of only piping.

B. Site assessor qualifications. If a tank or facility is located within a sensitive geologic area, as defined by this Chapter, the site assessment must be supervised by, and the site assessment report must be certified by, a Maine certified geologist, licensed professional engineer, or other persons meeting the requirements of Maine's professional regulation statutes and regulations for geologists or professional engineers practicing in Maine. As provided under 38 M.R.S. §563-B(1), the closure site assessment for facilities not located in a sensitive geologic area are exempt from the above qualification standards for the person conducting the assessment.

C. The findings of all site assessments conducted pursuant to this Chapter must be presented in a written report with supporting data, addressing the requirements of this appendix.

D. One paper copy and one digital PDF version of all site assessment reports conducted pursuant to this Chapter must be submitted to the Commissioner by the facility owner within 45 days of tank and piping removal or abandonment in place. The paper copy must be in an envelope endorsed "UST Site Assessment" and sent to the following address: UST Program Administrator, MDEP-BRWM, 17 SHS, Augusta ME 04333-0017. Electronic submittals must be submitted to UST. Site. Assessment@maine.gov with the tank registration #, address and municipality in the subject line.

If a site assessment finds evidence of a discharge or contamination above a notification level in Appendix Q, an additional paper copy of the site assessment report must be submitted at the same time, to the chief municipal official of the municipality within which the facility is located or to the county commissioners if located in an unorganized township.

NOTE: Upon receipt of a site assessment report, the Commissioner will review and determine if further investigation or remediation is needed in addition to any completed at the time of the facility abandonment in accordance with section 12.

E. Site assessment reports must follow the general format and include the following information:

(1) A completed summary cover sheet using the, form attached to this appendix;

(2) A description of the purpose of the site assessment per Appendix P (1),a description of the tanks and piping to be removed or abandoned in place, and a description of the areas to be assessed in the site assessment;

(3) Identification of the facility name and site location;

(4) A description of the facility and site history under Appendix P(5) when evidence of a discharge or contamination above notification levels in Appendix Q is found;

(5) Identification of all potential receptors under Appendix P(4) when evidence of a discharge or contamination above notification levels in Appendix Q is found;

(6) Description of the site assessment methods utilized, including field instrument methods, laboratory methods and quality assurance/quality control (QA/QC) procedures followed;

(7) Findings of the site assessment, including field and laboratory analytical results for all soil and water samples collected, a site plan showing the location and sample number of all soil and water samples; and

(8) Recommendations and conclusions.

F. The Commissioner may require sample location and quality data to be submitted in an electronic format compatible with the Maine Environmental and Geographic Analysis Database (EGAD). The format for such data will be provided by the Commissioner.

G. Exception for the removal of flexible primary piping when piping is being replaced. The site assessment requirements in paragraphs 2(B) through 2(E) do not apply to the removal of the flexible primary piping of double-walled piping when conducted in accordance with section 5(B) (6-A) of this Chapter and the following requirements.

(1) Prior notification by the facility owner or operator of the piping abandonment to the Commissioner and the municipality is provided in accordance with section 11(F) of this Chapter.

(2) Upon removal, the entire length of primary piping is visually inspected by a Maine Certified Underground Oil Storage Tank Installer and the physical condition and the integrity of the piping is documented, including any evidence of a discharge or leak.

(3) The Certified Underground Oil Storage Tank Installer submits to the Commissioner and the facility owner or operator the findings of the visual inspection on a reporting form provided by the Commissioner within 30 days of the piping abandonment and removal.

(4) Any oil discharge is reported to the Commissioner within 2 hours of discovery.

3. The following facility and site location information must be included in all site assessments:

A. Mailing and street address of facility;

B. Tax map and lot number;

C. Whether it is located in a sensitive geologic area as defined by this Chapter; and

D. UTM, longitude/latitude decimal coordinates, or Google Earth satellite photograph or comparable map showing the precise location of the facility dispensers, tanks, and piping runs.

4. The following information regarding potential receptors must be provided where contamination or evidence of a discharge of oil has been found:

A. A description of surrounding land uses and the extent of public drinking water service to all abutters and the surrounding area. A facility layout plan showing locations of property boundaries, tanks, product and vent lines, dispensers, subsurface waste water disposal systems, dry wells, floor drains, sewer lines and underground utilities;

B. Type of oil products discharged; and

C. Recommendations regarding the need for further investigation of the extent of contamination and the objectives of the remediation of the oil discharge, including the following:

(1) Free product and oil saturated soils;

(2) Protection and remediation of ground water, private public drinking water supplies, public drinking water supplies and their source water protection areas mapped by the Maine Drinking Water Program, and significant sand and gravel aquifers mapped by the Maine Geological Survey;

(3) Petroleum vapor intrusion or indoor air quality;

(4) Direct human contact to contaminated soils; and

(5) Surface water bodies.

5. If evidence of a discharge of oil is found, the site assessment must also include the following facility and site history information:

A. Product storage and distribution system history, including:

(1) Location of tanks or piping previously abandoned in place;

(2) Type of oil products most recently stored;

B. A list of all known prior oil and hazardous substance discharges and their Commissioner assigned spill number; and

C. Summary of the findings of previous available site assessments and contamination investigations.

6. Site assessment requirements for the removal of heavy oil storage facilities.

A. Tanks, piping and other underground facility components must be inspected visually upon removal for presence of holes, loose fittings and joints, cracks, fractures and evidence of oil stains. If any of the conditions above are found the facility owner or operator shall notify the Commissioner of the occurrence of a discharge within 2 hours of discovery.

B. The tank and piping excavation must be inspected visually for any evidence of a discharge of oil; including oil stained or saturated soil, strong petroleum vapors emitted from soil or free product or an oil sheen on ground water in the excavation. The presence of any of the above conditions is considered an indication of a discharge of oil and must be reported to the Commissioner within 2 hours of discovery by the facility owner or operator and before the excavation hole is filled. The owner shall immediately proceed with an investigation and corrective action measures in accordance with section 12.

C. The entire facility must be inspected visually for surface spills and discharges. Such spills and discharges must be reported to the Commissioner in accordance with section 12(A).

D. Upon visual discovery of evidence of a leak or discharge of oil at a heavy oil facility and reporting such to the Commissioner, the site assessment investigation at the time of closure may be terminated, except where a tank or piping was located on or in bedrock in which case the presence of contaminated ground water must be investigated in accordance with paragraph 9 below.

7. Site assessment requirements for motor fuel and marketing and distribution facilities when tanks or piping are removed and immediately replaced, or when an operating facility will remain.

A. Applicability. The requirements of this section apply when an underground oil storage facility or a portion thereof, is removed and then replaced with a new underground oil storage facility on the same land parcel, utilizing all or part of the same tank excavation hole. The requirements below also apply to situations when only a portion of a facility is removed and other parts of the facility remain in operation.

B. Tanks, piping and other underground facility components must be inspected visually upon removal for presence of holes, loose fittings and joints, cracks, fractures and evidence of oil stains. If any of the conditions above are found the facility owner or operator shall notify the Commissioner of the occurrence of a discharge within 2 hours of discovery.

C. The tank and piping excavation must be inspected visually for any evidence of a discharge of oil; including oil stained or saturated soil, strong petroleum vapors emitted from soil or free product or an oil sheen on ground water in the excavation. The presence of any of the above conditions is considered an indication of a discharge of oil and must be reported to the Commissioner within 2 hours of discovery by the facility owner or operator and before the excavation hole is filled. The owner shall immediately proceed with an investigation and corrective action measures in accordance with section 12.

NOTE: OSHA regulations governing entering excavations and confined spaces should be strictly followed. Excavations should not be entered if above 20 percent of the Lower Explosive Limit (LEL), or less than 19.2 percent or greater than 25 percent oxygen.

D. The entire facility must be inspected visually for surface spills and discharges. Such spills and discharges must be reported to the Commissioner in accordance with section 12(A) of this Chapter.

E. Oil contaminated soil assessment. Soil in the tank and piping excavation holes and under removed dispensers, as well as areas of identifiable surface spills, must be evaluated for oil contamination by one of the methods specified in Appendix Q.

8. Site assessment requirements for waste oil facilities, and motor fuel and marketing and distribution facilities when a facility is removed but not immediately replaced.

A. Applicability. The following requirements apply to all waste oil facilities. They also apply to motor fuel and marketing and distribution facilities when an underground oil storage facility is fully closed and removed without a replacement facility being immediately installed.

B. Tanks, piping and other underground facility components must be inspected visually upon removal for presence of holes, loose fittings and joints, cracks, fractures and evidence of oil stains. If any of the conditions above are found the facility owner or operator shall notify the Commissioner of the occurrence of a discharge within 2 hours of discovery.

C. The tank and piping excavation must be inspected visually for any evidence of a discharge of oil; including oil stained or saturated soil, strong petroleum vapors emitted from soil or free product or an oil sheen on ground water in the excavation. The presence of any of the above conditions is considered an indication of a discharge of oil and must be reported to the Commissioner within 2 hours of discovery by the facility owner or operator and before the excavation hole is filled. The owner shall immediately proceed with an investigation and corrective action measures in accordance with section 12.

D. The entire facility must be inspected visually for surface spills and discharges. Such spills and discharges must be reported to the Commissioner in accordance with section 12(A).

E. The facility and the surrounding area are to be evaluated prior to the facility removal to identify potential receptors and exposure pathways to facilitate remediation decisions in the event a discharge is discovered. At a minimum, these should include public drinking water supplies and their source water protection areas mapped by the Maine Drinking Water Program, private drinking water supplies, significant sand and gravel aquifers mapped by the Maine Geological Survey, surface water bodies, and occupied buildings potentially at risk in the event of vapor intrusion pathways. If known, the next land use of the facility parcel is to be identified and the potential for residents, recreation users, outdoor commercial workers and construction workers to be exposed to oil contaminated soils evaluated.

F. Oil contamination assessment. Soil in the tank and piping excavation holes and under dispensers, as well as areas of identifiable surface spills, are to be evaluated for oil contamination by one of the methods specified in Appendix Q.

9. Requirements for facilities installed on or in bedrock. In addition to other applicable site assessment requirements in this appendix, when a tank or piping run has been installed onto or in bedrock without adequate soil backfill or bedding to test for soil contamination, a minimum of two (2) down gradient ground water monitoring wells must be installed under the supervision of a Maine certified geologist or Maine licensed professional engineer in addition to above requirements of this appendix. Additional wells may be required by the Commissioner for tanks with more than 20,000 gallons capacity. Monitoring wells must be sampled for visual and olfactory evidence of oil as well as for dissolved phase product using a hydrocarbons laboratory analysis method meeting the requirements of Appendix S and appropriate for the oil products stored at the facility in the past. The detection of oil contamination must be reported to the Commissioner within 2 hours by the facility owner or operator. This paragraph applies to all removed facilities required to do a site assessment, including heavy oil facilities.

10. Site assessment requirements when tanks and piping are abandoned in place.

A. The requirements of this section apply whenever a facility or any portion of a facility are abandoned in place and are not removed. If a tank, piping section or other underground component is not removed, these requirements only apply to that particular portion of the entire facility.

B. Prior approval is required for abandonment in place in accordance with section 11(E).

C. All visible portions of the facility must be inspected for evidence of a leak, spill, overfill or other discharge, including areas around the fill and vent pipes.

D. Evidence of contaminated soils from a tank leak must be determined by either of the methods below:

(1) A minimum of two soil borings must be made per tank, located as close as technically feasible to intersect any oil contamination from the surface to below the estimated depth of the tank bottom or to bedrock or below the ground water table, whichever is shallower. An additional number of borings may be required by the Commissioner for tanks with more than 20,000 gallons capacity. The borings must be logged and screened continuously for visual evidence of oil stained and saturated soils, and oil vapors using a photo or flame ionization field instrument as removed from the ground. A sample must be taken from soil showing the highest reading for field analysis using a method outlined in paragraph 1 of Appendix Q or another Commissioner approved method of comparable accuracy and sensitivity.

(2) Other subsurface investigation methods approved by the Commissioner.

E. If piping cannot be removed such that entire excavation can be inspected, evidence of an oil discharge from the piping is to be evaluated using a methodology appropriate for the site conditions and approved in advance by the Commissioner.

F. When a facility was installed on or into bedrock, when borings encounter bedrock before reaching an elevation below that of the bottom of the tank or piping, or when ground water is encountered prior to reaching the depth below that of the tank or piping; a minimum of two ground water monitoring wells must be installed down gradient, as close as feasible. For tanks greater than 20,000 gallons capacity, the Commissioner may require additional monitoring wells. Monitoring wells samples must be inspected for visual and olfactory evidence of oil as well as analyzed for dissolved phase gasoline, diesel fuel or heating oil, depending on the oil products stored at the facility in the past. Only results from a laboratory method meeting the requirements of Appendix S will be accepted by the Commissioner. The detection of oil contamination must be reported to the Commissioner within 2 hours by the facility owner or operator.

G. When the above site assessment procedures for a facility to be abandoned in place are not technically feasible, another procedure may be used when approved by the Commissioner prior to the initiation of facility closure.

11. After-the-fact site assessments. For circumstances when an underground oil storage facility was previously removed without a site assessment to determine if oil contamination is present, a site specific investigation and sampling plan is required. Such a sampling plan should at a minimum include soil borings, test pits or other similar invasive means to collect soil samples to the depth of a typical tank installation, and describe the field and/or laboratory analytical methods proposed for use. The sampling plan must be submitted in advance of conducting the work for Commissioner approval. The Commissioner may require sampling of ground water, drinking water supplies, or surface water where warranted.

Chapter 691 Summary Cover Sheet Form for Underground Oil Storage Facility Site Assessment

The purpose of a site assessment for facility closure or abandonment is to determine if discharges of oil have occurred requiring notification of the Commissioner and corrective action by the owner, operator or another responsible party.

Facility hydro geological information to be verified by site assessor: Enter No or Yes below.

For facilities assessed: Enter tank & piping (chamber #) information below. For tank and piping status enter closed (C), not closed (NC), removed (R) or abandoned in place (AIP). Provide reference to report narrative for clarifications or inconsistencies with Notice of Intent to Remove.

Submittal Requirements: Each page of the site assessment report must be consecutively numbered. For email submissions, put DEP registration number, address and municipality name in email subject line and send to UST. Site. Assessment@maine.gov. Please note that the DEP may request additional paper copies.

If no "evidence" of a discharge or contamination above a notification level, please send one paper copy to UST Program Administrator, DEP-BRWM, 17 SHS, Augusta ME 04333-0017 and a digital PDF version to the above noted email address.

If yes "evidence" of a discharge or contamination above a notification level, please send one paper copy to the above noted postal address and a digital PDF version to the above noted email address and one copy to the chief municipal officer or county Commissioner if unorganized township (List name and address of municipal officer or county Commissioner here:).