Current through Register Vol. 63, No. 3, March 1, 2024
When a landfill owner or operator has installed a gas
collection and control system pursuant to OAR 340-239-0110, the owner or
operator may permanently shutdown and remove the system only as provided in
this rule.
(1) The gas collection and
control system at a closed landfill, or at a closed area of a landfill, may be
capped or removed provided all of the following requirements are met:
(a) The gas collection and control system was
in operation for at least 15-years, unless the owner or operator can
demonstrate to the satisfaction of DEQ that due to declining methane rates the
owner or operator of the landfill will be unable to operate the gas collection
and control system for a 15-year period.
(b) The calculated or measured methane
generation rate at the landfill is less than 664 metric tons (732 tons) per
year on three successive test dates. For measured methane generation rates, the
test dates must be no less than 90 days apart and no more than 180 days apart.
The calculated methane generation rate must be calculated pursuant to OAR
340-239-0800(2).
(c) Surface
methane concentration measurements of methane do not exceed 200 ppmv.
(d) The owner or operator submits an
Equipment Removal Report to DEQ pursuant to OAR 340-239-0700(3)(b).
(e) The concentration of methane gas at the
landfill does not exceed 25 percent of the lower explosive limit for methane
concentration in facility structures (excluding gas collection and control
system components) or the lower explosive limit for methane concentration at
the property boundary.
(2) The owner or operator of the landfill
that has capped or removed a gas collection and control system under section
(1) of this rule must conduct surface methane concentration measurements over
the portion of the landfill with the capped or removed gas collection and
control system pursuant to OAR 340-239-0800(3) for at least eight consecutive
calendar quarters after the gas collection and control system is capped or
removed. The measurements must comply with the following requirements:
(a) The walking grid in OAR
340-239-0800(3)(a)(B) may be reduced to 100-foot spacing so long as the walking
grid is offset by 25-feet each quarter so that by the end of one year of
monitoring, the entire surface area has been monitored every 25 feet;
(b) If there is no measured concentration of
methane of 200 ppmv or greater from the surface of the closed landfill in any
of these measurement events, the owner or operator must submit a final gas
collection and control system Closure Notification to DEQ pursuant to OAR
340-239-0700(3)(a); and
(c) If
there is any measured concentration of methane of 200 ppmv or greater in any of
these measurement events, other than nonrepeatable, momentary readings, as
determined by instantaneous surface emissions monitoring, from the surface of
the closed landfill, the owner or operator must comply with OAR 340-239-0110
through 340-239-0800.
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
