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) gallons per hour at ten (10) pounds per squareinch 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;
   2. (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
   3. (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 (Cum. Supp. 1989) and 644.026, RSMo (Cum. 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.