Wash. Rev. Code § 70A.540.030
(1) Each owner or operator of an active municipal solid waste landfill having fewer than 450,000 tons of waste in place must submit an annual waste in place report to the department or local authority pursuant to RCW 70A.540.070.
(b) The waste in place report must be submitted annually until either:
(2) Each owner or operator of either an active municipal solid waste landfill having greater than or equal to 450,000 tons of waste in place or a closed municipal solid waste landfill having greater than or equal to 750,000 tons of waste in place must calculate the landfill gas heat input capacity pursuant to RCW 70A.540.080 and the department's implementing rules and must submit a landfill gas heat input capacity report to the department or local authority.
(a) If the calculated landfill gas heat input capacity is less than 3,000,000 British thermal units per hour recovered, the owner or operator must:
(ii) Submit an annual landfill gas heat input capacity report to the department or local authority until either of the following conditions are met:
(b) If the landfill gas heat input capacity is greater than or equal to 3,000,000 British thermal units per hour recovered, the owner or operator must either:
(ii) Demonstrate to the satisfaction of the department or local authority that after four consecutive quarterly monitoring periods there is no measured concentration of methane of 200 parts per million by volume or greater using the instantaneous surface monitoring procedures specified in RCW 70A.540.080 and the department's implementing rules. Based on the monitoring results, the owner or operator must do one of the following:
(C) If there is no measured concentration of methane of 200 parts per million by volume or greater from the surface of a closed or inactive municipal solid waste landfill, the requirements of this chapter and the department's implementing rules adopted pursuant to RCW 70A.540.020 no longer apply, provided that the following information is submitted to and approved by the department or local authority:
[ 2022 c 179 s 3.]