Owners and operators of petroleum UST systems must provide release detection for tanks and piping as follows:
(a) Tanks. Tanks must be monitored at least every 30 days for releases using one of the methods listed in Sec. 280.43 (d) through (h) except that:
(1) UST systems that meet the performance standards in Sec. 280.20 or Sec. 280.21, and the monthly inventory control requirements in Sec. 280.43 (a) or (b), may use tank tightness testing (conducted in accordance with Sec. 280.43(c)) at least every 5 years until December 22, 1998, or until 10 years after the tank is installed or upgraded under Sec. 280.21(b), whichever is later;
(2) UST systems that do not meet the performance standards in Sec. 280.20 or Sec. 280.21 may use monthly inventory controls (conducted in accordance with Sec. 280.43(a) or (b)) and annual tank tightness testing (conducted in accordance with Sec. 280.43(c)) until December 22, 1998 when the tank must be upgraded under Sec. 280.21 or permanently closed under Sec. 280.71; and
(3) Tanks with capacity of 550 gallons or less may use weekly tank gauging (conducted in accordance with Sec. 280.43(b)).
(b) Piping. Underground piping that routinely contains regulated substances must be monitored for releases in a manner that meets one of the following requirements:
(1) Pressurized piping. Underground piping that conveys regulated substances under pressure must:
(i) Be equipped with an automatic line leak detector conducted in accordance with Sec. 280.44(a); and
(ii) Have an annual line tightness test conducted in accordance with Sec. 280.44(b) or have monthly monitoring conducted in accordance with Sec. 280.44(c).
(2) Suction piping. Underground piping that conveys regulated substances under suction must either have a line tightness test conducted at least every 3 years and in accordance with Sec. 280.44(b), or use a monthly monitoring method conduct in accordance with Sec. 280.44(c). No release detection is required for suction piping that is designed and constructed to meet the following standards:
(i) The below-grade piping operates at less than atmospheric pressure;
(ii) The below-grade piping is sloped so that the contents of the pipe will drain back into the storage tank if the suction is released;
(iii) Only one check valve is included in each suction line;
(iv) The check valve is located directly below and as close as practical to the suction pump; and
(v) A method is provided that allows compliance with paragraphs (b)(2) (ii)-(iv) of this section to be readily determined.