Release detection requirements for hazardous substance underground storage tank systems

Owners and operators of hazardous substance underground storage tank systems must provide containment that meets the following requirements and monitor these systems using subsection 7 of section 33.1-24-08-33 at least every thirty days: 1. Secondary containment systems must be designed, constructed, and installed: a. Contain regulated substances leaked from the primary containment until they are detected and removed; b. Prevent the release of regulated substances to the environment at any time during the operational life of the underground storage tank system; and c. Be checked for evidence of a release at least every thirty days. NOTE: The provisions of section 33.1-24-05-106 may be used to comply with this subsection for tanks installed on or before April 1, 2018. 2. Double-walled tanks must be designed, constructed, and installed to: a. Contain a leak from any portion of the inner tank within the outer wall; and b. Detect the failure of the inner wall. 3. External liners (including vaults) must be designed, constructed, and installed to: a. Contain one hundred percent of the capacity of the largest tank within its boundary; b. Prevent the interference of precipitation or ground water intrusion with the ability to contain or detect a release of regulated substances; and c. Surround the tank completely (for example, it is capable of preventing lateral as well as vertical migration of regulated substances). 4. Underground piping must be equipped with secondary containment that satisfies the requirements of subsection 1 (for example, trench liners, double-walled pipe). In addition, underground piping that conveys regulated substances under pressure must be equipped with an automatic line leak detector in accordance with subsection 1 of section 33.1-24-08-34. 5. For hazardous substance underground storage tank systems installed on or before April 1, 2018, other methods of release detection may be used if owners and operators: a. Demonstrate to the department that an alternate method can detect a release of the stored substance as effectively as any of the methods allowed in subsections 2 through 9 of section 33.1-24-08-33 can detect a release of petroleum; b. Provide information to the department on effective corrective action technologies, health risks, and chemical and physical properties of the stored substance, and the characteristics of the underground storage tank site; and c. Obtain approval from the department to use the alternate release detection method before the installation and operation of the new underground storage tank system.