Additions, exceptions, and alternatives for underground storage tank systems with field-constructed tanks and airport hydrant systems

1. Exception to piping secondary containment requirements. Owners and operators may use single-walled piping when installing or replacing piping associated with underground storage tank systems with field-constructed tanks greater than fifty thousand gallons and piping associated with airport hydrant systems. Piping associated with underground storage tank systems with field-constructed tanks less than or equal to fifty thousand gallons not part of an airport hydrant system must meet the secondary containment requirement when installed or replaced. 2. Upgrade requirements. No later than April 1, 2021, airport hydrant systems and underground storage tank systems with field-constructed tanks where installation commenced on or before April 1, 2018, must meet the following requirements or be permanently closed pursuant to sections 33.1-24-08-60 through 33.1-24-08-64. a. Corrosion protection. Underground storage tank system components in contact with the ground that routinely contain regulated substances must meet one of the following: (1) Except as provided in subsection 1, the new underground storage tank system performance standards for tanks at subsection 1 of section 33.1-24-08-10 and for piping at subsection 2 of section 33.1-24-08-10; or (2) Be constructed of metal and cathodically protected according to a code of practice developed by a nationally recognized association or independent testing laboratory and meets the following: (a) Cathodic protection must meet the requirements of paragraphs 2 through 4 of subdivision b of subsection 1 of section 33.1-24-08-10 for tanks, and paragraphs 2 through 4 of subdivision b of subsection 2 of section 33.1-24-08-10 for piping. (b) Tanks greater than ten years old without cathodic protection must be assessed to ensure the tank is structurally sound and free of corrosion holes prior to adding cathodic protection. The assessment must be by internal inspection or another method determined by the department to adequately assess the tank for structural soundness and corrosion holes. (NOTE: The following codes of practice may be used to comply with this section: NACE International Standard Practice SP 0285, "External Control of Underground Storage Tank Systems by Cathodic Protection", NACE International Standard Practice SP 0169, "Control of External Corrosion on Underground or Submerged Metallic Piping Systems"; National Leak Prevention Association Standard 631, Chapter C, "Internal Inspection of Steel Tanks for Retrofit of Cathodic Protection"; or American Society for Testing and Materials Standard G158, "Standard Guide for Three Methods of Assessing Buried Steel Tanks".) b. Spill and overfill prevention equipment. To prevent spilling and overfilling associated with product transfer to the underground storage tank system, all underground storage tank systems with field-constructed tanks and airport hydrant systems must comply with new underground storage tank system spill and overfill prevention equipment requirements specified in subsection 3 of section 33.1-24-08-10. 3. Walkthrough inspections. In addition to the walkthrough inspection requirements in section 33.1-24-08-26, owners and operators shall inspect the following additional areas for airport hydrant systems at least once every thirty days if confined space entry according to the occupational safety and health administration (see 29 CFR part 1910) is not required or at least annually if confined space entry is required and keep documentation of the inspection according to subsection 2 of section 33.1-24-08-26. a. Hydrant pits - Visually check for any damage, remove any liquid or debris, and check for any leaks; and b. Hydrant piping vaults - Check for any hydrant piping leaks. 4. Release detection. Owners and operators of underground storage tank systems with field- constructed tanks and airport hydrant systems shall begin meeting the release detection requirements described in sections 33.1-24-08-70 through 33.1-24-08-72 no later than April 1, 2021. a. Methods of release detection for field-constructed tanks. Owners and operators of field-constructed tanks with a capacity less than or equal to fifty thousand gallons shall meet the release detection requirements in sections 33.1-24-08-30 through 33.1-24-08-35. Owners and operators of field-constructed tanks with a capacity greater than fifty thousand gallons shall meet either the requirements in sections 33.1-24-08-30 through 33.1-24-08-35 (except subsections 5 and 6 of section 33.1-24-08-33 must be combined with inventory control as stated below) of this chapter or use one or a combination of the following alternative methods of release detection: (1) Conduct an annual tank tightness test that can detect a one-half gallon per hour leak rate; (2) Use an automatic tank gauging system to perform release detection at least every thirty days that can detect a leak rate less than or equal to one gallon per hour. This method must be combined with a tank tightness test that can detect a two-tenths gallon per hour leak rate performed at least every three years; (3) Use an automatic tank gauging system to perform release detection at least every thirty days that can detect a leak rate less than or equal to two gallons per hour. This method must be combined with a tank tightness test that can detect a two-tenths gallon per hour leak rate performed at least every two years; (4) Perform vapor monitoring (conducted in accordance with subsection 5 of section 33.1-24-08-33 for a tracer compound placed in the tank system) capable of detecting a one-tenth gallon per hour leak rate at least every two years; (5) Perform inventory control (conducted in accordance with department of defense Directive 4140.25, ATA Airport Fuel Facility Operations and Maintenance Guidance Manual, or equivalent procedures) at least every thirty days that can detect a leak equal to or less than one-half percent of flowthrough; and (a) Perform a tank tightness test that can detect a one-half gallon per hour leak rate at least every two years; or (b) Perform vapor monitoring or groundwater monitoring (conducted in accordance with subsections 5 and 6 of section 33.1-24-08-33, respectively, for the stored regulated substance) at least every thirty days; or (6) Another method approved by the department if the owner and operator can demonstrate the method can detect a release as effectively as any of the methods allowed in paragraphs 1 through 5. In comparing methods, the department shall consider the size of release the method can detect and the frequency and reliability of detection. b. Methods of release detection for piping. Owners and operators of underground piping associated with field-constructed tanks less than or equal to fifty thousand gallons shall meet the release detection requirements in sections 33.1-24-08-30 through 33.1-24-08-35. Owners and operators of underground piping associated with airport hydrant systems and field-constructed tanks greater than fifty thousand gallons shall follow either the requirements in sections 33.1-24-08-30 through 33.1-24-08-35 (except subsections 5 and 6 of section 33.1-24-08-33 must be combined with inventory control as stated below) of this chapter or use one or a combination of the following alternative methods of release detection: (1) Perform a semiannual or annual line tightness test at or above the piping operating pressure in accordance with the table below. Maximum Leak Detection Rate Per Test Section Volume Test Section Volume (Gallons) Semiannual Test - Leak Detection Rate Not To Exceed (Gallons Per Hour) Annual Test - Leak Detection Rate Not To Exceed (Gallons Per Hour) <50,000 1.0 0.5 ≥50,000 to < 75,000 1.5 0.75 ≥75,000 to < 100,000 2.0 1.0 ≥100,000 3.0 1.5 Piping segment volumes greater than or equal to one hundred thousand gallons not capable of meeting the maximum three gallon per hour leak rate for the semiannual test may be tested at a leak rate up to six gallons per hour according to the following schedule: Phase-In For Piping Segments ≥ 100,000 Gallons In Volume First test Not later than April 1, 2021, (may use up to 6.0 gph leak rate) Second test Between April 1, 2021, and April 1, 2024, (may use up to 6.0 gph leak rate) Third test Between April 1, 2024, and April 1, 2025, (must use 3.0 gph for leak rate) Subsequent tests After April 1, 2025, begin using semiannual or annual line testing according to the Maximum Leak Detection Rate Per Test Section Volume table above (2) Perform vapor monitoring (conducted in accordance with subsection 5 of section 33.1-24-08-33 for a tracer compound placed in the tank system) capable of detecting a one-tenth gallon per hour leak rate at least every two years; (3) Perform inventory control (conducted in accordance with department of defense Directive 4140.25, ATA Airport Fuel Facility Operations and Maintenance Guidance Manual, or equivalent procedures) at least every thirty days that can detect a leak equal to or less than one-half percent of flowthrough; and (a) Perform a line tightness test (conducted in accordance with paragraph 1 of subdivision b using the leak rates for the semiannual test) at least every two years; or (b) Perform vapor monitoring or groundwater monitoring (conducted in accordance with subsections 5 and 6 of section 33.1-24-08-33, respectively, for the stored regulated substance) at least every thirty days; or (4) Another method approved by the department if the owner and operator can demonstrate the method can detect a release as effectively as any of the methods allowed in paragraphs 1 through 3. In comparing methods, the department shall consider the size of release the method can detect and the frequency and reliability of detection. c. Recordkeeping for release detection. Owners and operators shall maintain release detection records according to the recordkeeping requirements in section 33.1-24-08-35. 5. Applicability of closure requirements to previously closed underground storage tank systems. When directed by the department, the owner and operator of an underground storage tank system with field-constructed tanks or airport hydrant system permanently closed before April 1, 2018, shall assess the excavation zone and close the underground storage tank system in accordance with sections 33.1-24-08-60 through 33.1-24-08-64 if releases from the underground storage tank may, in the judgment of the department, pose a current or potential threat to human health and the environment.