USTs containing any substance listed in Appendix A of this chapter are hazardous substance USTs. Owners and/or operators of hazardous substance UST systems shall provide release detection that meets the following requirements:
(a) Release detection: Hazardous substance UST systems shall have a secondary containment system, be constructed with double walled tanks, or be constructed with an external liner or vault surrounding the entire tank system. These systems shall meet the following requirements: - (i) Secondary containment systems shall:
- (A) be designed, constructed and installed to contain regulated substances released from the tank system until those substances are detected and removed;
- (B) be designed, constructed and installed to prevent the release of regulated substances to the environment at any time during the operational life of the UST system; and
- (C) be inspected for evidence of a release at least once every thirty (30) days.
- (ii) Double-walled tanks shall:
- (A) Be designed, constructed, and installed to contain a release from any portion of the inner tank within the outer wall;
- (B) Be designed, constructed, and installed to detect the failure of the inner wall; and
- (C) Be inspected for evidence of a release at least once every thirty (30) days.
- (iii) External liners, (including vaults) shall:
- (A) Be designed, constructed, and installed to contain one hundred percent (100%) of the capacity of the largest tank within its boundary;
- (B) Be designed, constructed, and installed to prevent the interference of precipitation or groundwater intrusion with the ability to contain or detect a release of regulated substances;
- (C) Be designed, constructed, and installed to surround the tank completely (i.e., it is capable of preventing lateral as well as vertical migration of regulated substances); and
- (D) Be inspected for evidence of a release at least every thirty (30) days.
(b) Connected Piping: Connected piping shall be equipped with secondary containment that satisfies the requirements of this section. Trench liners and double-walled pipe are examples of secondary containment systems. Connected piping that conveys regulated substances under pressure shall be equipped with an automatic line leak detector in accordance with Section 14(g)(i).
(c) Other methods: Other methods of release detection may be used if owners and/or operators: - (i) Demonstrate to the department that an alternate method can detect a release of the stored regulated substance as effectively as any of the methods allowed in Section 16(b) through (h) can detect a release of petroleum;
- (ii) 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 UST site; and
- (iii) Obtain authorization from the department to use the alternate release detection method before the installation and operation of the new or modified UST system.
020-17 Wyo. Code R. § 17-17