PURPOSE: This rule describes the requirements of leak detection for the piping on underground storage tanks.

1. (1) Each method of release detection for piping used to meet the requirements of release detection for underground storage tanks

2. (UST) in 10 CSR 20-10.041 must be conducted in the following manner:

   1. (A) Automatic Line Leak Detectors. Methods which alert the operator to the presence of a leak by restricting or shutting off the flow of regulated substances through piping or triggering an audible or visual alarm may be used only if they detect leaks of three

3. (3) gallons per hour at ten (10) pounds per square-inch line pressure within one (1) hour. An annual test of the operation of the leak detector must be conducted in accordance with the manufacturer’s requirements;

   1. (B) Line Tightness Testing. A periodic test of piping may be conducted only if it can detect a one-tenth (0.1)-gallon-per-hour leak rate at one and one-half (1.5) times the operating pressure; and
   2. (C) Applicable Tank Methods. Any of the methods in 10 CSR 20-10.043(1)(E)—(H) may be used if they are designed to detect a release from any portion of the underground piping that routinely contains regulated substances.

AUTHORITY: sections 319.107, RSMo Supp. 1989 and 644.026, RSMo Supp. 1993.* Original rule filed April 2, 1990, effective Sept. 28, 1990.

*Original authority: 319.107, RSMo 1989 and 644.026, RSMo 1972, amended 1973, 1987, 1993. 10 CSR 20-10