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-J - Requirements for Abandonment of Underground Oil Storage Tanks by Removal

Current through 2024-29, July 17, 2024
1. The top of the tank must be exposed.
2. All piping must be drained and flushed into the tank or
				  other suitable container such that no waste water or product is released to the
				  environment (1 or 2 gallons of water should be sufficient to flush
				  piping).
3. All liquid that can be pumped out must be removed, and any
				  liquids that cannot be used for their originally intended purpose must be
				  disposed of in accordance with the Department's
Waste Oil Management
				  Rules
, 06-096 C.M.R. ch. 860. UL listed explosion proof equipment must
				  be used to remove Class I liquids. Hoses to remove product must be inserted to
				  the low end of the tank, which may still contain product. Flammable vapors from
				  vacuum trucks removing oil from a tank or facility must be vented at least 12
				  feet above the ground surface.
4. The fill (drop) tube must be removed. Fill, gauge, and
				  product lines must be disconnected. The open ends of all lines must be capped
				  or plugged. All tank openings that will not be used in the inerting procedure
				  also must be plugged. Only the vent line will remain connected and open until
				  the inerting procedure is complete. The vent line must be at least 12 feet
				  above the ground surface.
NOTE: Due to the potential of waste oil tank explosions, the
				  Department strongly recommends treating all waste oil tanks as a Class I liquid
				  tank except where testing shows the internal atmosphere not to be
				  explosive.
5. All tanks that contained Class I liquids must be made safe
				  prior to removing the tank from the ground using one of the following
				  methods:
A. The tank can be inerted with dry ice in the amount of 1.5
				  pounds per 100 gallons of tank capacity. Dry ice shall be crushed and
				  distributed evenly over the greatest possible area. During the inerting
				  process, all necessary precautions to prevent ignition in the entire area shall
				  be taken.
B. The tank can be inerted using nitrogen or another inert
				  gas approved by the Commissioner, introduced at low pressure at the bottom of
				  the tank. Inerting is considered complete when oxygen levels in the tank are
				  measured at less than 6 percent.
C. The tank can be removed if the tank atmosphere is found to
				  be oxygen deficient as defined by an oxygen reading of less than 6
				  percent.
D. The tank can be rendered vapor free by air purging in
				  accordance with API 1604. Air purging is considered complete when an
				  explosimeter indicates an atmosphere inside the tank of less than 10 percent of
				  the LEL while an oxygen meter indicates greater than 14 percent oxygen. Air
				  purging using air-moving equipment found on a vacuum truck is not
				  allowed.
During any of the above inerting, purging or removal
				  procedures, all necessary precautions to prevent ignition in the area must be
				  taken, including but not limited to: grounding and bonding of equipment; use of
				  explosion proof or intrinsically safe equipment; ambient air monitoring of the
				  surrounding area; and pedestrian and traffic control. All weather and ambient
				  atmospheric conditions must be evaluated prior to inerting or purging,
				  including but not limited to air exchange, wind direction and humidity. All air
				  monitoring instruments must be calibrated according to the manufacturer's
				  specifications. Measurements with air monitoring instruments must be taken at
				  the following points: one foot from the bottom of the tank; at its lowest end;
				  the middle of the tank's diameter; and at the tank opening.
NOTE: All contaminated soil must be removed or otherwise
				  cleaned up to the satisfaction of the Commissioner.
6. All holes, including corrosion holes, must be plugged or
				  capped before the tank is moved from the site, except that one 1/8 inch vent
				  hole must be left to prevent the tank from being subjected to an excessive
				  pressure differential caused by extreme temperature changes.
7. If transported, the tanks must be scraped to remove all
				  loose backfill material adhering to the tank.
8. All tanks removed from the ground, regardless of
				  condition, must be labeled with the following information: Tank Has Contained
				  Leaded Gasoline (or Flammable Liquid) NOT GAS FREE.
NOTE: U.S. Department of Transportation regulations,
Hazardous Materials Regulations
, 49 C.F.R. §
				  172.500-172.560 also require tanks which have not been purged but are being
				  transported to be labeled on the ends and sides with a "Flammable" placard with
				  the appropriate UN Number (1203 or 1993) attached.
9. If transported, the tank must be secured on a truck such
				  that the 1/8 inch vent hole is located on the uppermost point on the
				  tank.
10. All piping must be removed from the ground whenever
				  practicable. Piping that cannot be removed must be blown clear of residual
				  product with an inert gas and securely plugged at all ends. All necessary
				  precautions to prevent spillage or ignition in the entire area must be
				  taken.
11. Some tank disposal facilities require that tanks be
				  cleaned of sludge and residues prior to accepting the tank. Any cleaning and
				  temporary storage operations must be performed at a site acceptable to local
				  public safety officials and not on a sensitive geologic area, as defined in
				  section
				  3 of this Chapter. Any cleaning
				  operation involving flammable materials or generating flammable vapors must be
				  performed at a remote site where public access can be restricted by fencing or
				  other suitable means 24 hours/day. Tank cleaning may be performed at the site
				  where the tank is removed only with the permission of the local public safety
				  official.
NOTE: If cleaning a tank at the site of its removal, it is
				  recommended that the tank be cleaned while still in its excavation hole, the
				  safest location in the event of an explosion or fire.
12. The only acceptable means of disposal of underground oil
				  storage tanks are:
A. Sale to a properly approved junk or scrap dealer;
B. Disposal at a tank processing facility meeting the
				  criteria of Appendix L of these rules and approved by the Department; or
C. Other techniques for disposal of tanks, provided the
				  expressed written approval of the Department and the State Fire Marshal's
				  office has been obtained.
13. Tanks must be stored with all bung holes open and
				  positioned at a 45 degree angle down from horizontal to prevent rain from
				  entering the tank and to allow vapors to escape.