PURPOSE: This rule contains the new options for release detection for the previously deferred field-constructed tanks and airport hydrant fuel distribution piping systems.

1. (1) Owners and operators of bulk underground piping associated with any airport hydrant fuel distribution systems and fieldconstructed tanks greater than fifty thousand (>50,000) gallons may use one (1) or a combination of the following alternative methods of release detection:

   1. (A) Perform a biannual or annual bulk line tightness test at or above operating pressure in accordance with the table below. Bulk piping segments greater than or equal to one hundred thousand (≥100,000) gallons not capable of meeting the maximum three (3.0) gallons-per-hour leak rate for the biannual test may be tested at a leak rate up to six (6.0) gallons-per-hour:

      Maximum Detectable Leak Rate Per Test Section Volume

Test Section Biannual Test Maximum Annual Test Volume Detectable Leak Rate Maximum Detectable (Gallons) (Gallons-Per- Hour) Leak Rate (Gallons- Per- Hour) < 50,000 1.0 0.5 1.5 0.75 (cid:149) 50,000 to < 75,000 2.0 1.0 (cid:149) 75,000 to < 100,000 3.0 1.5 (cid:149) 100,000

1. (B) Perform vapor monitoring, with an added tracer chemical, conducted in accordance with 10 CSR 26-2.043(1)(F), capable of detecting a one-tenth- (0.1-) gallon-perhour leak rate at least every two (2) years;

2. (C) Perform inventory control, conducted in accordance with Department of Defense Directive 4140.25; ATA Airport Fuel Facility Operations and Maintenance Guidance Manual, at least every thirty (30) days that can detect a leak equal to or less than one-half percent (0.5%) of flow-through. When using this method, the following must also be met:

   1. 1. Perform a line tightness test in accor-

dance with the biannual test threshold in subsection (A) of this section at least every two (2) years; or

1. 2. Perform vapor monitoring or ground-

water monitoring in accordance with 10 CSR 26-2.043 subsection (1)(F) or (G), respectively, at least every thirty (30) days;

1. (D) Another method approved by the department if the owner and operator can demonstrate that the method can detect a release as effectively as any of the methods allowed in subsections (A) through (C). In comparing methods, the department shall consider the size of release that the method can detect and the frequency and reliability of detection. If the method is approved, the owner and operator must comply with any conditions imposed by the department on its use.

AUTHORITY: sections 319.105, 319.107, and 319.137, RSMo 2016.* Original rule filed Aug. 15, 2016, effective May 30, 2017. *Original authority: 319.105, RSMo 1989; 319.107, RSMo 1989, amended 1994; and 319.137, RSMo 1989, amended 1993, 1995, 2004.