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-D - Installation Requirements Applicable to New and Replacement Tanks

Current through 2024-29, July 17, 2024
1. All new and replacement tanks and associated leak
				  detection and overfill and spill prevention equipment must be installed in
				  accordance with manufacturer's instructions and the following nationally
				  accepted codes of practice: API Publication 1615, "Installation of Underground
				  Petroleum Storage Systems"; PEI Publication RP 100, "Recommended Practices for
				  Installation of Underground Liquid Storage Systems"; and National Fire
				  Protection Association Code 30, 30A or 31.
NOTE: Tank installation instructions may require specific
				  sized pea stone or gravel. Instructions also may specify mechanical compaction
				  or layered placement of bedding and backfill. Always consult the installation
				  instructions provided by the manufacturer, prior to installation.
2. Cathodically protected steel tanks must be set on a firm
				  base and surrounded on all sides with at least 24 inches of noncorrosive inert
				  material, such as clean sand, pea stone, or gravel, well tamped in place. The
				  tanks must be placed in the hole with care, making sure not to scrape the
				  protective coating off coated tanks, or damage attached cathodic protection
				  components. Cathodic protection systems require electrical wiring connected to
				  the tank at each end and at its centerline, and accessible for voltage readings
				  at the ground surface as well as three (3) locations along the centerline of
				  the tank to place a reference electrode in contact with the soil.
3. Cathodically protected steel underground tanks must be
				  covered with a minimum of 2 feet of sand, pea stone or gravel, or with not less
				  than 1 foot of sand on top of which is placed a slab of reinforced concrete not
				  less than 4 inches thick. This fill must be free of debris, boulders, large
				  rocks or other materials that may cause abrasions to the protective coating of
				  the tank. When tanks are, or are likely to be, subjected to traffic, they must
				  be protected from damage from vehicles passing over them by at least 3 feet of
				  backfill or, 18 inches of well-tamped backfill plus 6 inches of reinforced
				  concrete or 8 inches of asphalt paving. When asphalt or reinforced concrete
				  paving is used as part of the protection, it must extend at least 1 foot
				  horizontally beyond the perimeter of the tank in all directions.
4. All cathodically protected steel and nonmetallic
				  fiberglass tanks must be installed in accordance with manufacturer
				  instructions. The minimum depth of cover is as specified in section
				  3 above.
5. New underground tanks must be tested for tightness before
				  being covered or placed in use by a test method approved by the manufacturer.
				  If a pneumatic test is conducted, it should be done in conformance with the
				  requirements of Appendix C.
NOTE: Air pressure testing when petroleum vapors are present
				  in the tank may result in explosion, and shall not be conducted after petroleum
				  product has been placed in the tank.
6. All temporary supports must be removed prior to final
				  backfilling.
7. All electrical wiring must be performed in accordance with
				  the current State of Maine electrical code.
8. Anchoring is required when a tank is installed in an area
				  where ground water will be in contact with the tank or in a 100 year flood
				  plain as mapped by the FEMA, or if such mapping is unavailable, as determined
				  by the flood of record or by the presence of flood plain soils. When anchoring
				  tanks equipped with cathodic protection, the holddowns must be electrically
				  isolated from the tank. Anchoring of all tanks must be performed in accordance
				  with the tank manufacturer's specification or PEI Publication RP 100.
NOTE: FEMA flood plain maps are available for inspection at
				  most municipal offices.