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RWM Home > Programs > Underground Oil Storage Tanks > UST Additional Information > Installation, Registration and Retrofits > Siting Underground Oil Storage Tanks

Siting Underground Oil Storage Tanks

Maine has a law to protect public and private water supplies

THE BASICS OF THE LAW:

Link: An Act To Prevent Contamination of Drinking Water Supplies

Legislative intent:

In 2001 the Maine legislature passed a law to protect existing public and private water supplies, as well as future water supplies( i.e. sand and gravel aquifers), from the threats of spills and leaks from Underground Oil Storage Tanks.

Summary of the law

  • It prohibits the installation of new underground oil storage tank (UST) facilities, such as gas stations and bulk fuel plants, in areas where an installation is likely to pose a threat to drinking water. The specific prohibitions are:
  • No new USTs within the source water protection area of a public drinking water supply, or within 1000 feet of the public water supply (whichever is greater)*; and
  • No new USTs within 300 feet of a private water supply (except for a private water supply well located on the same property as a facility and serving only that facility).
  • The law applies to new motor fuel (gasoline, diesel, aviation fuel) facilities and to facilities for the marketing and distribution of oil (bulk fuel plants storing any type of oil product). Heating oil tanks for use on the premises are exempt.

Variances:

The law allows the commissioner of the Department of Environmental Protection to grant a variance from these prohibitions in certain limited circumstances.

  • For community public water systems and ground water serving schools and private wells, a variance is available only where no hydrogeological connection between the proposed facility location and the potentially affected water supply can be demonstrated. The demonstrations requires submitting a hydrogeological study to DEP for approval.
  • For other types of public drinking water supply systems, a variance may be issued if the commissioner determines that the engineering and monitoring measures proposed by the applicant go beyond current minimum regulatory requirements and that they will effectively minimize releases of oil and the likelihood of groundwater contamination.

An opportunity for public comment is required on each request for a variance.

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  • *DEFINITIONS: A source water protection area is the land area that contributes recharge water to a public drinking water supply well. Maps of these areas are available from the Drinking Water Program (287-8074) and most municipal offices. Public wells range from wells serving an entire community, a mobile home park, schools and large places of business to campgrounds, restaurants and motels. Maps showing the general location of public wells are available on the Web at http://www.maine.gov/dhhs/eng/water/ (look under maps).

Failure to comply with the law:

  • The DEP commissioner is authorized to halt the operation of any facility installed in violation of these prohibitions.
  • Clean-up costs and 3rd party damages caused by discharges from a facility installed in violation of these prohibitions are not eligible for reimbursement from the State’s Ground Water Oil Clean-up Fund.

Additional regulations:

The law required the adoption of regulations to govern the siting of new underground storage facilities if those facilities are used to store motor fuels or used in the marketing or distribution of oil and are located within significant sand and gravel aquifers and their recharge areas. (Maps are currently available for inspection at most municipal offices and from the Maine Geologic Society for a small fee.)

These rules may be found in section 3-A of of Chapter 691, the Department's Rules for Underground Oil Storage Facilities.

BACKGROUND ON THE LAW:

  • Lack of basic siting standards for USTs: Until 2001 there was no statutory requirement that potential threats to drinking water be considered as part of the permit process governing installation of underground oil storage tank facilities. Between 1995 and 2000, 128 new underground storage tank (UST) motor fuel facilities were registered and constructed in Maine and 55, or 43%, are located in sensitive geological areas. These facilities have a combined storage capacity of 871, 600 gallons of gasoline and other motor fuels.
  • No tank is 100% leak-proof: New and replacement UST facilities are equipped with secondary containment, leak detection and overfill protection. However, operational errors, installation errors, other human errors and routine equipment failures due to wear and tear continue to result in discharges to the environment.

A July , 2000, study examined a random (10%) sample of active oil UST facilities. Twenty-five percent of 262 facilities did not conduct required annual operation and maintenance inspections. Of those that did, 29% found equipment that was not functioning properly. The most common problems involved overfill prevention equipment, tank leak detection, and leak detection equipment for pressurized piping. When problems were discovered, they frequently (39% of the time) went uncorrected.

  • The economic benefit of encouraging siting away from drinking water resources is estimated in the millions of dollars. The cost of investigating and remediating sites in sensitive areas is generally greater than elsewhere in Maine. Five of the 55 new motor fuel facilities located in sensitive areas have reported a spill or leak that has contaminated soil and groundwater. To date, the total clean-up cost for these five is approximately $1.7 million. This translates to an average $339,300 per site. In comparison, the statewide 1995-1999 average cost of a leaking underground storage tank cleanup was approximately $42,000
  • The installation of new underground oil storage facilities in areas where they could threaten drinking water is an unacceptable public health risk. At these sites, humans are at significant risk of exposure to toxic chemicals that include known carcinogens (benzene) or suspected carcinogens (MTBE) from their drinking water.
  • For more information on the costs and impacts of oil pollution from spills and leaks at underground oil storage facilities located near drinking water supplies or on sand and gravel aquifers, see the DEP’s Bureau of Remediation & Waste Management’s website: homepage.htm

For questions about this new law, please call George Seel or David McCaskill at 287-2651.

For more on the siting issue, see: Siting of New Underground Oil & Hazardous Substance Storage Facilities in Relation to Drinking Water Supplies & Significant Ground Water Resources - January 2001. Findings and conclusions of the Task Force to Protect Public Water Supplies.