Section 265.1057 - Standards: Valves in gas/vapor service or in light liquid service(a) Each valve in gas/vapor or light liquid service shall be monitored monthly to detect leaks by the methods specified in § 265.1063(b) and shall comply with paragraphs (b) through (e) of this section, except as provided in paragraphs (f), (g), and (h) of this section, and §§ 265.1061 and 265.1062 .(b) If an instrument reading of 10,000 ppm or greater is measured, a leak is detected.(c)(1) Any valve for which a leak is not detected for two successive months may be monitored the first month of every succeeding quarter, beginning with the next quarter, until a leak is detected.(2) If a leak is detected, the valve shall be monitored monthly until a leak is not detected for 2 successive months.(d)(1) When a leak is detected, it shall be repaired as soon as practicable, but no later than 15 calendar days after the leak is detected, except as provided in § 265.1059 .(2) A first attempt at repair shall be made no later than 5 calendar days after each leak is detected.(e) First attempts at repair include, but are not limited to, the following best practices where practicable: (1) Tightening of bonnet bolts.(2) Replacement of bonnet bolts.(3) Tightening of packing gland nuts.(4) Injection of lubricant into lubricated packing.(f) Any valve that is designated, as described in § 265.1064(g)(2) , for no detectable emissions, as indicated by an instrument reading of less than 500 ppm above background, is exempt from the requirements of paragraph (a) of this section if the valve: (1) Has no external actuating mechanism in contact with the hazardous waste stream.(2) Is operated with emissions less than 500 ppm above background as determined by the method specified in § 265.1063(c) .(3) Is tested for compliance with paragraph (f)(2) of this section initially upon designation, annually, and at other times as requested by the Regional Administrator.(g) Any valve that is designated, as described in § 265.1064(h)(1) , as an unsafe-to-monitor valve is exempt from the requirements of paragraph (a) of this section if:(1) The owner or operator of the valve determines that the valve is unsafe to monitor because monitoring personnel would be exposed to an immediate danger as a consequence of complying with paragraph (a) of this section.(2) The owner or operator of the valve adheres to a written plan that requires monitoring of the valve as frequently as practicable during safe-to-monitor times.(h) Any valve that is designated, as described in § 265.1064(h)(2) , as a difficult-to-monitor valve is exempt from the requirements of paragraph (a) of this section if: (1) The owner or operator of the valve determines that the valve cannot be monitored without elevating the monitoring personnel more than 2 meters above a support surface.(2) The hazardous waste management unit within which the valve is located was in operation before June 21, 1990.(3) The owner or operator of the valve follows a written plan that requires monitoring of the valve at least once per calendar year.