Current through Register Vol. 48, No. 38, September 20, 2024
a) This
Section applies to all units that dispose putrescible wastes.
b) Location and Design of Monitoring Wells
1) Gas monitoring devices must be placed at
intervals and elevations within the waste to provide a representative sampling
of the composition and buildup of gases within the unit.
2) Gas monitoring devices must be placed
around the unit at locations and elevations capable of detecting migrating gas
from the ground surface to the lowest elevation of the liner system or the top
elevation of the groundwater, whichever is higher.
3) A predictive gas flow model may be
utilized to determine the optimum placement of monitoring points required for
making observations and tracing the movement of gas.
4) Gas monitoring devices must be constructed
from materials that will not react with or be corroded by the landfill
gas.
5) Gas monitoring devices must
be designed and constructed to measure pressure and allow collection of a
representative sample of gas.
6)
Gas monitoring devices must be constructed and maintained to minimize gas
leakage.
7) The gas monitoring
system must not interfere with the operation of the liner, leachate collection
system, or delay the construction of the final cover system.
8) At least three ambient air monitoring
locations must be chosen and samples must be taken no higher than 0.025 meter
(1 inch) above the ground and 30.49 m (100 feet) downwind from the edge of the
unit or at the property boundary, whichever is closer to the unit.
c) Monitoring Frequency
1) All gas monitoring devices, including the
ambient air monitors must be operated to obtain samples on a monthly basis for
the entire operating period and for a minimum of five years after
closure.
2) After a minimum of five
years after closure, monitoring frequency may be reduced to quarterly sampling
intervals.
3) The sampling
frequency may be reduced to yearly sampling intervals upon the installation and
operation of a gas collection system equipped with a mechanical device such as
a compressor to withdraw gas.
4)
Monitoring must be continued for a minimum period of: 30 years after closure at
MSWLF units, except as otherwise provided by subsections (c)(5) and (c)(6);
five years after closure at landfills, other than MSWLF units, which are used
exclusively for disposing of wastes generated at the site; or 15 years after
closure at all other landfills regulated under this Part. Monitoring, beyond
the minimum period, may be discontinued if the following conditions have been
met for at least one year:
A) The
concentration of methane is less than five percent of the lower explosive limit
in air for four consecutive quarters at all monitoring points outside the unit;
and
B) Monitoring points within the
unit indicate that methane is no longer being produced in quantities that would
result in migration from the unit and exceed the standards of subsection
(a)(1).
5) The Agency
may reduce the gas monitoring period at an MSWLF unit upon a demonstration by
the owner or operator that the reduced period is sufficient to protect human
health and environment.
6) The
owner or operator of an MSWLF unit must petition the Board for an adjusted
standard in accordance with Section
811.303, if the
owner or operator seeks a reduction of the postclosure care monitoring period
for all of the following requirements:
A)
Inspection and maintenance (Section
811.111
);
B) Leachate collection (Section
811.309
);
C) Gas monitoring (Section
811.310); and
D) Groundwater
monitoring (Section
811.319
).
BOARD NOTE: Those segments of this subsection (c) that relate
to MSWLF units are derived from
40 CFR
258.61 (2017).
d) Parameters to be Monitored
1) All below ground monitoring devices must
be monitored for the following parameters at each sampling interval:
A) Methane;
B) Pressure;
C) Oxygen; and
D) Carbon dioxide.
2) Ambient air monitors must be sampled for
methane only when the average wind velocity is less than eight kilometers (five
miles) per hour at a minimum of three downwind locations 30.49 meters (100
feet) from the edge of the unit or the property boundary, whichever is closer
to the unit.
3) All buildings
within a facility must be monitored for methane by utilizing continuous
detection devices located at likely points where methane might enter the
building.
e) Any
alternative frequencies for the monitoring requirement of subsection (c) for
any owner or operator of an MSWLF that disposes of 20 tons (18 megagrams) of
municipal solid waste per day or less, based on an annual average, must be
established by an adjusted standard pursuant to Section 28.1 of the Act and
Subpart D of 35 Ill. Adm. Code 104. Any alternative monitoring frequencies
established under this subsection (e) must fulfill the following requirements:
1) They must consider the unique
characteristics of small communities;
2) They must take into account climatic and
hydrogeologic conditions; and
3)
They must be protective of human health and the environment.
BOARD NOTE: This subsection (e) is derived from
40 CFR
258.23(e) (2017).