PURPOSE: This rule outlines the minimum requirements for leak and spill detection systems. (1) Owners and operators of new and existing underground storage tank (UST) systems must provide a method, or combination of methods, of release detection that—

1. (A) Can detect a release from any portion of the tank and the connected underground piping that routinely contains product;
2. (B) Is installed, calibrated, operated and maintained in accordance with the manufacturer’s instructions, including routine maintenance and service checks for operability or running condition; and
3. (C) Meets the performance requirements for tanks in 10 CSR 20-10.043 or for piping in 10 CSR 20-10.044, with any performance claims and their manner of determination described in writing by the equipment manufacturer or installer. In addition, methods used after December 22, 1990, except for methods permanently installed prior to that date, must be capable of detecting the leak rate or quantity specified for that tank method in 10 CSR 20-10.043(1)(B)—(D) or piping method in 10 CSR 20-10.044(1)(A) and (B) with a probability of detection of ninety-five percent (95%) and a probability of false alarm of five percent (5%).
4. (2) When a release detection method for tanks in 10 CSR 20-10.043 or for piping in 10 CSR 20-10.044 indicates a release may have occurred, owners and operators must notify the department in accordance with 10 CSR 20-10.050—10 CSR 20-10.053.

5. (3) Owners and operators of all UST systems must comply with the release detection requirements of 10 CSR 20-10.040—10 CSR 20-10.045 by the following dates based on the year of installation:

   1. (A) December 22, 1990 for all existing pressurized piping;
   2. (B) September 28, 1990 for USTs installed before 1965, or of unknown age;
   3. (C) December 22, 1990 for USTs installed during 1965—1969;
   4. (D) December 22, 1991 for USTs installed during 1970—1974;
   5. (E) December 22, 1992 for USTs installed during 1975—1979;
   6. (F) December 22, 1993 for USTs installed during 1980—September 28, 1990; and
   7. (G) Immediately upon installation for any USTs installed after September 28, 1990.
6. (4) Any existing UST system that cannot apply a method of release detection that complies with the requirements of 10 CSR 20- 10.040—10 CSR 20-10.045 must complete the closure procedures in 10 CSR 20- 10.070—10 CSR 20-10.074 by the date on 10 CSR 20-10

which release detection is required for that UST system under section (3) of this rule.

AUTHORITY: sections 319.107 (Cum. Supp. 1989) and 644.026, RSMo (Cum. Supp. 1993).* Original rule filed April 2, 1990, effective Sept. 28, 1990. Amended: Filed Aug. 3, 1993, effective April 9, 1994. *Original authority: 319.107, RSMo (1989) and 644.026, RSMo (1972), amended 1973, 1987, 1993.