(a) Methods. AST owners and/or operators shall provide leak detection for the tank using one of the following methods: - (i) Automatic Tank Gauging. AST owners and/or operators using this method shall conduct automatic tank gauging in accordance with Section 16(c). Automatic tank gauges used for ASTs shall be third-party certified for use in an AST.
- (ii) Manual Tank Gauging. Owners and/or operators of ASTs with a capacity of less than 1,320 gallons may monitor the tanks using manual tank gauging in accordance with Section 15(a).
- (iii) Interstitial Monitoring. Owners and/or operators of ASTs that were constructed under UL Standard 2085, as referenced in Section 2, shall monitor the interstitial space between the inner tank and the outer shell. Records shall be kept showing the date of the monitoring, the name of the person doing the monitoring and the monitoring results. Monthly sensor status printouts from an automatic system may be used to meet this requirement.
- (iv) Visual Monitoring of Tank Bottoms. Owners and/or operators of ASTs that are elevated aboveground, and the entire surface of the tank is visible from beneath, shall monitor the tanks monthly for visible signs of leakage. Records of these inspections shall be made showing the date of the inspection, the name of the person doing the inspection, and any sign of leakage noted. Records shall be kept by the owner and/or operator for 3 years.
- (v) Passive Acoustic Sensing. If passive acoustic sensing is used, the AST shall be equipped with a continuous sensing system. This system shall be capable of detecting a release of 0.2 gallons per hour or a release of 150 gallons per month with a probability of detection of 0.95 and a probability of false alarm of 0.05. All passive acoustic sensing systems shall produce a written record showing that the system is on and operable. All passive acoustic sensing systems shall be calibrated annually.
- (vi) Tracer Surveys. Tracer surveys shall be conducted on a monthly basis in accordance with Section 16(h).
- (vii) Another method approved in accordance with Section 16(i).
(b) ASTs With a Capacity of 100,000 Gallons or Larger. Owners and/or operators of ASTs with a capacity of 100,000 gallons or more shall follow the inspection requirements of API Standard 653, as referenced in Section 2.
(c) SPCC Plans. Owners and/or operators of any single AST or combination of more than one AST, with a capacity of 1,320 gallons or more, shall have a Spill Prevention Control and Countermeasures (SPCC) Plan on file with the department. This is the same document required by the Environmental Protection Agency under 40 CFR 112 as referenced in Section 2.
(d) Additional Requirements for Large Facilities. Facilities with above ground capacity of 100,000 gallons or more shall provide at least one additional leak detection method beyond the requirements for Section 36(a). Such methods may be custom designed for the facility at the option of the owner and/or operator, or may be a second method named in Section 36(a). Department approval is required before implementing methods in compliance with this Section.
(e) Inventory Control. ASTs shall be monitored using inventory control in accordance with Section 16(a) unless the tank and all lines are isolated from ground contact and can be visually monitored, or the tank is isolated from ground contact and the connected underground piping is double-wall and interstitially monitored.
(f) Operator's Annual Inspection. Owners and/or operators of ASTs shall conduct an annual inspection of all AST systems in accordance with Section 13(g).
020-1 Wyo. Code R. § 1-36