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-B - Requirements for Tank, Piping and Containment Sump Tightness Tests

Current through 2024-29, July 17, 2024
1.
Volumetric tank tightness testing for single-walled
				  tanks
A. For all tanks without overfill and spill prevention
				  equipment installed in accordance with section
				  5(B)(3) or
				  6(B)(3) and properly
				  operating, all tests must be conducted by overfilling the tank at least to
				  grade level. For tanks with operating overfill and spill prevention equipment
				  meeting the requirements of this Chapter, tests may be conducted if the tank is
				  at least 60 percent full, provided the test is in accordance with manufacturer
				  protocols and with any limitations determined by independent testing in
				  accordance with EPA approved protocols, or other protocols approved by a
				  nationally recognized independent testing organization, including but not
				  limited to the ASTM and the National Work Group on Leak Detection
				  Evaluations.
B. All tests must take into consideration all variables which
				  may affect the determination of a leak rate, including, but not limited to,
				  temperature, pressure, external water table elevation, vapor pockets and tank
				  end deformation.
C. External water table elevation must be verified via a tank
				  back fill ground water observation well at the time of testing for each tank
				  location. The observation well is to be installed in accordance with paragraph
				  6(C) of this appendix.
D. All tests must be performed in strict conformity to all of
				  the testing equipment manufacturer's operating procedures, and the following
				  standard protocols:
(1) Tests must not be conducted during a fluctuating ground
				  water table;
(2) Height-to-volume conversion factors must be measured
				  rather than calculated;
(3) The test must be conducted under nearly constant
				  hydrostatic pressure; and
(4) If the tank is less than 95 percentfull during the
				  volumetric test then the ullage space must also be tested using an appropriate
				  tank tightness test method.
2.
Non-volumetric tightness testing for single walled
				  tanks
A. Non-volumetric and all other tank tightness tests must be
				  performed in strict conformity to the manufacturer's protocols as used in the
				  method's independent performance testing.
B. The ground water elevation must be measured at the time of
				  testing via a ground water observation well installed in accordance with
				  paragraph 6(C) of this appendix. If ground water is encountered in the
				  observation well, a sample is to be taken and visually inspected for the
				  presence of free product.
3. Tightness testing for single-walled piping
A. All pressurized product piping tests must be performed at
				  150 percent operating pressure, or if performed at a lower pressure, it must be
				  able to obtain a leak rate equivalent or smaller than that determined by the
				  piping test method's independent performance testing in accordance with EPA
				  approved protocols.
B. All tests must be performed in strict conformity to all of
				  the testing equipment manufacturer's standard operating procedures. In
				  addition, the test must be run a minimum of one hour.
C. Tightness testing requirements for single-walled safe
				  suction piping are considered to be met when a Maine Certified Underground Oil
				  Storage Tank Installer or Inspector confirms in writing that each suction line
				  is properly sloped back to the tank, and there is only one check valve in each
				  line installed as close as practical to the pump.
4.
Tightness testing of tanks and piping with secondary
				  containment
For double walled tanks and piping, the integrity of both the
				  inner and outer walls will be tested by testing the interstitial space rather
				  than the primary containment. Tanks and piping with secondary containment shall
				  be tested in accordance with sections
				  4 and
				  5 of the PEI Recommended Practice for
				  Testing and Verification of Spill, Overfill, Leak Detection and Secondary
				  Containment Equipment at UST Facilities, PEI 1200 or in accordance with
				  protocols reviewed and approved by the Commissioner prior to use.
5.
Tightness testing of containment sumps
Containment sumps will be tested by an alternative procedure
				  approved by the Commissioner, or in accordance with testing procedures outlined
				  in section
				  6 of the Petroleum Equipment
				  Institute, Recommended Practices for Testing and Verification of Spill,
				  Overfill, Leak Detection and Secondary Containment Equipment at UST Facilities,
				  PEI 1200, or the manufacturer's instructions.
6.
Other requirements
A. Testing technicians shall be certified by the manufacturer
				  of the testing equipment.
B. The additional requirements of this paragraph apply to the
				  testing of single-walled tanks used to store ethanol blended gasoline.
(1) Tightness tests must be conducted with 10 or less inches
				  of product in the tank using a test method approved for use with such product
				  levels; and
(2) The tank must be tested manually for water and
				  phase-separated gasoline.
C. Ground water elevation observation well installation. The
				  observation well to determine the elevation of ground water is to be installed
				  in the sand, gravel or pea stone backfill of the tank excavation to a depth of
				  one (1) to two (2) feet below the tank bottom in accordance with EPI
				  Recommended Practice 100. The observation well is to be a minimum of 1 inch in
				  diameter and may be installed using direct push technology. The well is to be
				  constructed of factory screened PVC pipe. Well screening is to start 5 feet
				  above the ground water table and extend to the bottom of the well. Wells are to
				  be installed flush with the ground surface and in a raised, limited access road
				  box. The annulus around the well must be sealed with bentonite or a similar
				  sealing material from 2 feet above the screen upward to the bottom of the road
				  box. Permeables and must be placed around the road box so that water can drain
				  from the road box. A Maine Certified Underground Tank Installer must be present
				  during the installation of the well to minimize the risk to the structural
				  integrity of the facility.
D. Tank and piping tightness tests involving the removal and
				  reinstallation of existing facility components, including but not limited to,
				  leak detection or overfill prevention equipment, drop tubes, or vent valves,
				  must have an Underground Oil Storage Tank Installer or Inspector present to
				  supervise such facility equipment removals and repairs. The installer or
				  inspector must be certified by BUSTI and by the manufacturer of the equipment
				  being repaired, when such manufacturer certification is available. Tank testing
				  involving excavation above, around or within 10 feet to tanks or piping also
				  requires a Maine Certified Tank Installer to be present to supervise such
				  excavation in accordance with section
				  5(D)(19) of this
				  Chapter.
E. All test results must include the following information in
				  order to be accepted by the Commissioner:
(1) Facility name, address, registration and tank number, and
				  the product stored;
(2) Depth to ground water and whether free product was found
				  in the ground water observation well;
(3) Whether the facility components tested passed or failed,
				  and the measured leak rate;
(4) The method's threshold for declaring a leak; and
(5) Certification that the test method has been performed
				  according to the manufacturer's protocols used in the third party evaluation,
				  or a protocol for double-walled tanks approved by the Commissioner, and that
				  ground water elevation was measured and taken into account in determining if a
				  leak was present.
F. Written test results must be submitted to the Commissioner
				  by the facility owner and the tester when conducted to verify evidence of a
				  possible leak. Routine annual precision tests conducted to meet the
				  requirements of section
				  5(C)(2)(a) or
				  5(F) of this Chapter
				  need only to be submitted by the facility owner.