Or. Admin. R. 340-239-0200 - Compliance Standards

When required as provided in OAR 340-239-0100 through 340-239-0800, the owner or operator of a landfill must comply with this rule.

(1) Surface Emission Methane Concentration Limits. Except as provided in OAR 340-239-0110(4), 340-239-0110(5), 340-239-0300, and 340-239-0600(1), beginning August 1, 2022, or upon commencing operation of a newly installed gas collection and control system or modification of an existing gas collection and control system pursuant to OAR 340-239-0110(1), whichever is later, no location on the landfill surface may exceed either of the following methane concentration limits:

(a) 500 ppmv, other than nonrepeatable, momentary readings, as determined by instantaneous surface emissions monitoring conducted in accordance with OAR 340-239-0800(3)(b);

(b) An average methane concentration limit of 25 ppmv as determined by integrated surface emissions monitoring conducted in accordance with OAR 340-239-800(3)(c).

(2) Wellhead Gauge Pressure Requirement: Each landfill gas collection and control system wellhead must be operated under a negative pressure without causing air infiltration, except as provided in OAR 340-239-0110(4) and 340-239-110(5), or under any of the following conditions:

(a) Use of a geomembrane or synthetic cover. The owner or operator must develop acceptable pressure limits for the wellheads and include them in the Design Plan;

(b) A decommissioned well. A well may experience a static positive pressure after shut down to accommodate for declining flows; or

(c) A fire or increased well temperature. The owner or operator must record instances when positive pressure occurs in efforts to avoid a fire. These records must be submitted with the semi-annual reports as provided in OAR 340-239-700(3)(c).

(3) Wellhead Temperature Requirement:

(a) Each landfill gas collection and control system interior wellhead in the collection system must be operated with a landfill gas temperature less than 62.8 degrees Celsius (145 degrees Fahrenheit).

(b) The landfill owner or operator may request a higher operating temperature value at a particular well. A higher operating value demonstration must be submitted to DEQ for approval and must include supporting data demonstrating that the elevated parameter neither causes fires nor significantly inhibits anaerobic decomposition by killing methanogens. The demonstration must satisfy both criteria in order to be approved (i.e., it is only acceptable if it neither causes fires nor kills methanogens).

Notes

Or. Admin. R. 340-239-0200

DEQ 16-2021, adopt filed 10/04/2021, effective 10/4/2021

Statutory/Other Authority: ORS 468.020, ORS 468A.025, ORS 468A.040 & ORS 468A.050

Statutes/Other Implemented: ORS 468A.025, ORS 468A.040 & ORS 468A.050