Current through Register Vol. 63, No. 3, March 1, 2024
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).
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
