Current through Register Vol. 41, No. 3, September 23, 2024
A. The provisions
of 9VAC5-40-20(Compliance) apply.
B. Owners subject to 9VAC5-40-5820 shall
comply with the provisions of Part III (9VAC20-81-100 et seq.) of 9VAC20
Chapter 81 (Solid Waste Management Regulations) pertaining to the control of
landfill gases.
C. Except as
provided in 9VAC5-40-5820 C 2 a (2), the specified methods in subdivisions C 1
through C 6 of this section shall be used to determine whether the gas
collection system is in compliance with 9VAC5-40-5820 C 2 b.
1. For the purposes of calculating the
maximum expected gas generation flow rate from the landfill to determine
compliance with 9VAC5-40-5820 C 2 b (1) (a), one of the following equations
shall be used. The k and L sub0 kinetic factors should be those published in
the "Compilation of Air Pollutant Emission Factors (AP-42)" (see 9VAC5-20-21)
or other site-specific values demonstrated to be appropriate and approved by
the board. If k has been determined as specified in 9VAC5-40-5860 B 4, the
value of k determined from the test shall be used. A value of no more than 15
years shall be used for the intended use period of the gas mover equipment. The
active life of the landfill is the age of the landfill plus the estimated
number of years until closure.
a. For sites
with unknown year-to-year solid waste acceptance rate:
QM =
2L0R(e-kc -
e-kt)
where
QM = maximum expected gas
generation flow rate, cubic meters per year
L0 = methane generation potential,
cubic meters per megagram solid waste
R = average annual acceptance rate, megagrams per
year
k = methane generation rate constant,
year-1
t = age of the landfill at equipment installation plus
the time the owner or operator intends to use the gas mover equipment or active
life of the landfill, whichever is less. If the equipment is installed after
closure, t is the age of the landfill at installation, years
c = time since closure, years (for an active landfill c =
0 and e-kc = 1)
b. For sites with known year-to-year solid
waste acceptance rate:
View Image
where
QM = maximum expected gas
generation flow rate, cubic meters per year
k = methane generation rate constant,
year-1
L0 = methane generation potential,
cubic meters per megagram solid waste
Mi = mass of solid waste in the
ith section, megagrams
ti = age of the
ith section, years
c. If a collection and control system has
been installed, actual flow data may be used to project the maximum expected
gas generation flow rate instead of, or in conjunction with, the equations in
subdivisions C 1 a and b of this section. If the landfill is still accepting
waste, the actual measured flow data will not equal the maximum expected gas
generation rate, so calculations using the equations in subdivisions C 1 a or b
of this section or other methods acceptable to the board shall be used to
predict the maximum expected gas generation rate over the intended period of
use of the gas control system equipment.
2. For the purposes of determining sufficient
density of gas collectors for compliance with 9VAC5-40-5820 C 2 b (1) (b), the
owner shall design a system of vertical wells, horizontal collectors, or other
collection devices, acceptable to the board, capable of controlling and
extracting gas from all portions of the landfill sufficient to meet all
operational and performance standards.
3. For the purpose of demonstrating whether
the gas collection system flow rate is sufficient to determine compliance with
9VAC5-40-5820 C 2 b (1) (c), the owner shall measure gauge pressure in the gas
collection header at each individual well, monthly. If a positive pressure
exists, action shall be initiated to correct the exceedance within five
calendar days, except for the three conditions allowed under 9VAC5-40-5822 A 2.
If negative pressure cannot be achieved without excess air infiltration within
15 calendar days of the first measurement, the gas collection system shall be
expanded to correct the exceedance within 120 days of the initial measurement
of positive pressure. Any attempted corrective measure shall not cause
exceedances of other operational or performance standards. An alternative
timeline for correcting the exceedance may be submitted to the board for
approval.
4. Owners are not
required to expand the system as required in subdivision C 3 of this section
during the first 180 days after gas collection system startup.
5. For the purpose of identifying whether
excess air infiltration into the landfill is occurring, the owner shall monitor
each well monthly for temperature and nitrogen or oxygen as provided in
9VAC5-40-5822 A 3. If a well exceeds one of these operating parameters, action
shall be initiated to correct the exceedance within five calendar days. If
correction of the exceedance cannot be achieved within 15 calendar days of the
first measurement, the gas collection system shall be expanded to correct the
exceedance within 120 days of the initial exceedance. Any attempted corrective
measure shall not cause exceedances of other operational or performance
standards. An alternative timeline for correcting the exceedance may be
submitted to the board for approval.
6. An owner seeking to demonstrate compliance
with 9VAC5-40-5820 C 2 b (1) (d) through the use of a collection system not
conforming to the specifications provided in 9VAC5-40-5824 shall provide
information acceptable to the board as specified in 9VAC5-40-5820 C 2 a (3)
demonstrating that off-site migration is being controlled.
D. For purposes of compliance with
9VAC5-40-5822 A 1, each owner of a controlled landfill shall place each well or
design component as specified in the approved design plan as provided in
9VAC5-40-5820 C 2 a. Each well shall be installed no later than 60 days after
the date on which the initial solid waste has been in place for a period of:
1. Five years or more if active; or
2. Two years or more if closed or at final
grade.
E. The following
procedures shall be used for compliance with the surface methane operational
standard as provided in 9VAC5-40-5822 A 4.
1.
After installation of the collection system, the owner shall monitor surface
concentrations of methane along the entire perimeter of the collection area and
along a pattern that traverses the landfill at 30-meter intervals (or a
site-specific established spacing) for each collection area on a quarterly
basis using an organic vapor analyzer, flame ionization detector, or other
portable monitor meeting the specifications provided in subsection F of this
section.
2. The background
concentration shall be determined by moving the probe inlet upwind and downwind
outside the boundary of the landfill at a distance of at least 30 meters from
the perimeter wells.
3. Surface
emission monitoring shall be performed in accordance with § 4.3.1 of
Reference Method 21 of Appendix A of 40 CFR Part 60, except that the probe
inlet shall be placed within 5 to 10 centimeters of the ground. Monitoring
shall be performed during typical meteorological conditions.
4. Any reading of 500 parts per million or
more above background at any location shall be recorded as a monitored
exceedance and the actions specified in subdivisions E 4 a through e of this
section shall be taken. As long as the specified actions are taken, the
exceedance is not a violation of the operational requirements of 9VAC5-40-5822
A 4.
a. The location of each monitored
exceedance shall be marked and the location recorded.
b. Cover maintenance or adjustments to the
vacuum of the adjacent wells to increase the gas collection in the vicinity of
each exceedance shall be made and the location shall be remonitored within 10
calendar days of detecting the exceedance.
c. If the remonitoring of the location shows
a second exceedance, additional corrective action shall be taken and the
location shall be monitored again within 10 days of the second exceedance. If
the remonitoring shows a third exceedance for the same location, the action
specified in subdivision E 4 e of this section shall be taken, and no further
monitoring of that location is required until the action specified in
subdivision E 4 e of this section has been taken.
d. Any location that initially showed an
exceedance but has a methane concentration less than 500 parts per million
methane above background at the 10-day remonitoring specified in subdivision E
4 b or c of this section shall be remonitored one month from the initial
exceedance. If the one-month remonitoring shows a concentration less than 500
parts per million above background, no further monitoring of that location is
required until the next quarterly monitoring period. If the 1-month
remonitoring shows an exceedance, the actions specified in subdivision E 4 c or
e of this section shall be taken.
e. For any location where monitored methane
concentration equals or exceeds 500 parts per million above background three
times within a quarterly period, a new well or other collection device shall be
installed within 120 calendar days of the initial exceedance. An alternative
remedy to the exceedance, such as upgrading the blower, header pipes or control
device, and a corresponding timeline for installation may be submitted to the
board for approval.
5.
The owner shall implement a program to monitor for cover integrity and
implement cover repairs as necessary on a monthly basis.
F. Each owner seeking to comply with the
provisions in subsection E of this section shall comply with the following
instrumentation specifications and procedures for surface emission monitoring
devices:
1. The portable analyzer shall meet
the instrument specifications provided in § 3 of Reference Method 21 of
Appendix A of 40 CFR Part 60, except that "methane" shall replace all
references to VOC.
2. The
calibration gas shall be methane, diluted to a nominal concentration of 500
parts per million in air.
3. To
meet the performance evaluation requirements in § 3.1.3 of Reference
Method 21 of Appendix A of 40 CFR Part 60, the instrument evaluation procedures
of § 4.4 of Reference Method 21 of Appendix A of 40 CFR Part 60 shall be
used.
4. The calibration procedures
provided in § 4.2 of Reference Method 21 of Appendix A of 40 CFR Part 60
shall be followed immediately before commencing a surface monitoring
survey.
G. The
provisions of this article apply at all times, except during periods of
startup, shutdown, or malfunction, provided that the duration of startup,
shutdown, or malfunction shall not exceed five days for collection systems and
shall not exceed one hour for treatment or control devices. This subsection
shall not apply to the emission standards set forth in 9VAC5-40-5830 and
9VAC5-40-5840.
H. With regard to
startup, shutdown, and malfunction, the provisions of 9VAC5-40-5850 A and
9VAC5-40-5910 shall apply to the emission standards set forth in 9VAC5-40-5830
and 9VAC5-40-5840.
Statutory Authority
§ 10.1-1308 of the Code of Virginia; §§
110, 111, 123, 129, 171, 172, and 182 of the Clean Air Act; 40 CFR Parts 51 and
60.
