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-E - Installation Requirements for New and Replacement Piping

Current through 2024-29, July 17, 2024
1. All new and replacement piping, sumps and associated leak
				  detection must be installed in accordance with the 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", STI Standard R 892, and NFPA 30, 30A and 31.
2. Before underground piping is installed, the trench must
				  receive as a minimum a 6-inch deep bed of well compacted noncorrosive material
				  such as clean sand, pea stone or gravel. All trenches must be wide enough to
				  permit at least 6 inches of noncorrosive backfill material around all
				  lines.
3. Prior to being covered or placed in service, all new and
				  replacement piping must be tested for tightness by a method approved by the
				  manufacturer. Air pressure tests are to be conducted in accordance with the
				  requirements of Appendix C, and hydrostatic tests must be conducted in
				  accordance with the requirements of Appendix B.
4. All temporary supports must be removed prior to final
				  backfilling.
5. All vent piping for storage of Class I liquids must extend
				  at least 12 feet above the ground surface and be positioned such that vapors
				  will not pose a hazardous condition. Vent piping must slope back to the tank
				  with a slope of at least 1/8inch per foot.
6. Fill piping for storage of Class I liquids must be set
				  back from any building opening in accordance with National Fire Protection
				  Association Codes 30, 30A or 31.
7. Product supply lines used in conjunction with pressurized
				  pumping systems must be installed with a product line leak detection device.
				  All leak detection devices must be tested for proper operation before the
				  remote pumping system is used after initial installation and once annually
				  thereafter. All leak detectors must be capable of detecting a leak at a rate of
				  at least 3 gallons per hour at a line pressure of 10 psi within one hour of
				  occurrence with a 95 percent probability of detection and a 5 percent
				  probability of false alarm.
8. A double-poppet crash valve must be installed under
				  dispensers of pressurized pumping systems in accordance with the National Fire
				  Protection Code 30A.
9. Safe suction systems must have no more than one check
				  valve per pump. The check valve must be located as close to the pump as
				  possible, such that any leaks in the line will result in a return of product to
				  the tank. Safe suction piping must slope back to the tank with at least a
				  1/8inch per foot slope. Supply and return piping for a facility storing oil for
				  an emergency standby generator are exempt from this requirement if secondary
				  containment with continuous interstitial space monitoring is provided in
				  accordance with section
				  5(B)(2) of this
				  Chapter.
10. When the product dispenser of a motor fuel facility is at
				  a lower elevation than all or a portion of the tank height, an anti-siphon
				  ("normally closed") valve must be installed as close as physically possible to
				  the start of the down-gradient run of the product piping in order to prevent
				  the loss of the tank contents in the event of a piping leak.