Current through Register Vol. 41, No. 3, September 23, 2024
A. The provisions of 9VAC5-40-30 (Emission
testing) or 40 CFR
60.8, whichever is more restrictive,
apply.
B.
1. The owner shall calculate the NMOC
emission rate using either the equation provided in subdivision B 1 a of this
section or the equation provided in subdivision B 1 b of this section. Both
equations may be used if the actual year-to-year solid waste acceptance rate is
known, as specified in subdivision B 1 a of this section, for part of the life
of the landfill and the actual year-to-year solid waste acceptance rate is
unknown, as specified in subdivision B 1 b of this section, for part of the
life of the landfill. The values to be used in both equations are 0.05 per year
for k, 170 cubic meters per megagram for L0, and 4,000
parts per million by volume as hexane for the CNMOC. For
landfills located in geographical areas with a 30-year average annual
precipitation of less than 25 inches, as measured at the nearest representative
official meteorological site, the k value to be used is 0.02 per year.
a. The following equation shall be used if
the actual year-to-year solid waste acceptance rate is known.
MNMOC =
View
Image2kL0Mi
(e-kti) (CNMOC)
(3.6 X 10-9)
where
MNMOC = Total NMOC emission rate
from the landfill, megagrams 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
CNMOC = concentration of NMOC,
parts per million by volume as hexane
3.6 X 10-9 = conversion
factor
The mass of nondegradable solid waste may be subtracted
from the total mass of solid waste in a particular section of the landfill when
calculating the value for Mi if documentation of the
nature and amounts of such wastes is obtained.
b. The following equation shall be used if
the actual year-to-year solid waste acceptance rate is unknown.
MNMOC = 2L0
R(e-kc
-e-kt)(CNMOC)(3.6 X
10-9)
where
MNMOC = mass emission rate of
NMOC, megagrams 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 landfill, years
CNMOC = concentration of NMOC,
parts per million by volume as hexane
c = time since closure, years. For active landfill c = 0
and e-kc = 1
3.6 X 10-9 = conversion
factor
The mass of nondegradable solid waste may be subtracted
from the total mass of solid waste in a particular section of the landfill when
calculating the value of R if documentation of the nature and amounts of such
waste is maintained.
2. Tier 1. The owner shall compare the
calculated NMOC mass emission rate to the following emission rate applicability
criteria:
(i) in the Northern Virginia
Volatile Organic Compound Emissions Control Area, 23 megagrams per year or
(ii) in the remaining areas of the
Commonwealth, 50 megagrams per year.
a. If the
NMOC emission rate calculated in subdivision B 1 of this section is (i) 23
megagrams per year in the Northern Virginia Volatile Organic Compound Emissions
Control Area or (ii) 50 megagrams per year in the remaining areas of the
Commonwealth, then the owner shall submit an emission rate report as provided
in 9VAC5-40-5880 D 1, and shall recalculate the NMOC mass emission rate
annually as required under 9VAC5-40-5820 C 1.
b. If the calculated NMOC emission rate is
greater than or equal to (i) 23 megagrams per year in the Northern Virginia
Volatile Organic Compound Emissions Control Area or (ii) 50 megagrams per year
in the remaining areas of the Commonwealth, then the owner shall either comply
with 9VAC5-40-5820 C 2, or determine a site-specific NMOC concentration and
recalculate the NMOC emission rate using the procedures provided in subdivision
B 3 of this section.
3. Tier 2. The owner shall determine the NMOC
concentration using the following sampling procedure. The owner shall install
at least two sample probes per hectare of landfill surface that has retained
waste for at least two years. If the landfill is larger than 25 hectares in
area, only 50 samples are required. The sample probes should be located to
avoid known areas of nondegradable solid waste. The owner shall collect and
analyze one sample of landfill gas from each probe to determine the NMOC
concentration using Reference Method 25C of Appendix A of 40 CFR Part 60 or
Reference Method 18 of Appendix A of 40 CFR Part 60. If using Reference Method
18 of Appendix A of 40 CFR Part 60, the minimum list of compounds to be tested
shall be those published in the "Compilation of Air Pollutant Emission Factors
(AP-42)" (see 9VAC5-20-21). If composite sampling is used, equal volumes shall
be taken from each sample probe. If more than the required number of samples
are taken, all samples shall be used in the analysis. The owner shall divide
the NMOC concentration from Reference Method 25C of Appendix A of 40 CFR Part
60 by six to convert from CNMOC as carbon to
CNMOC as hexane.
a. The
owner shall recalculate the NMOC mass emission rate using the equations
provided in subdivision B 1 a or B 1 b of this section and using the average
NMOC concentration from the collected samples instead of the default value in
the equation provided in subdivision B 1 of this section.
b. If the resulting mass emission rate
calculated using the site-specific NMOC concentration is greater than or equal
to (i) 23 megagrams per year in the Northern Virginia Volatile Organic Compound
Emissions Control Area or (ii) 50 megagrams per year in the remaining areas of
the Commonwealth, then the owner shall either comply with 9VAC5-40-5820 C 2, or
determine the site-specific methane generation rate constant and recalculate
the NMOC emission rate using the site-specific methane generation rate using
the procedure specified in subdivision B 4 of this section.
c. If the resulting NMOC mass emission rate
is less than (i) 23 megagrams per year in the Northern Virginia Volatile
Organic Compound Emissions Control Area or (ii) 50 megagrams per year in the
remaining areas of the Commonwealth, the owner shall submit a periodic estimate
of the emission rate report as provided in 9VAC5-40-5880 D 1 and retest the
site-specific NMOC concentration every five years using the methods specified
in this section.
4. Tier
3. The site-specific methane generation rate constant shall be determined using
the procedures provided in Reference Method 2E of Appendix A of 40 CFR Part 60.
The owner shall estimate the NMOC mass emission rate using equations in
subdivision B 1 a or B 1 b of this section and using a site-specific methane
generation rate constant k, and the site-specific NMOC concentration as
determined in subdivision B 3 of this section instead of the default values
provided in subdivision B 1 of this section. The owner shall compare the
resulting NMOC mass emission rate to the following emission rate applicability
criteria:
(i) in the Northern Virginia
Volatile Organic Compound Emissions Control Area, 23 megagrams per year or
(ii) in the remaining areas of the
Commonwealth, 50 megagrams per year.
a. If the
NMOC mass emission rate as calculated using the site-specific methane
generation rate and concentration of NMOC is greater than or equal to (i) 23
megagrams per year in the Northern Virginia Volatile Organic Compound Emissions
Control Area or (ii) 50 megagrams per year in the remaining areas of the
Commonwealth, the owner shall comply with 9VAC5-40-5820 C 2.
b. If the NMOC mass emission rate is less
than (i) 23 megagrams per year in the Northern Virginia Volatile Organic
Compound Emissions Control Area or (ii) 50 megagrams per year in the remaining
areas of the Commonwealth, then the owner shall submit a periodic emission rate
report as provided in 9VAC5-40-5880 D 1 and shall recalculate the NMOC mass
emission rate annually, as provided in 9VAC5-40-5880 D 1 using the equations in
subdivision B 1 of this section and using the site-specific methane generation
rate constant and NMOC concentration obtained in subdivision B 3 of this
section. The calculation of the methane generation rate constant is performed
only once, and the value obtained from this test shall be used in all
subsequent annual NMOC emission rate calculations.
5. The owner may use other methods
to determine the NMOC concentration or a site-specific k as an alternative
method required in subdivisions B 3 and B 4 of this section if the method has
been approved by the board.
C. After the installation of a collection and
control system in compliance with 9VAC5-40-5850, the owner shall calculate the
NMOC emission rate for purposes of determining when the system can be removed
as provided in 9VAC5-40-5820 C 2 e, using the following equation:
MNMOC = 1.89 X
10-3 QLFG
CNMOC
where
MNMOC = mass emission rate of
NMOC, megagrams per year
QLFG = flow rate of landfill gas,
cubic meters per minute
CNMOC = NMOC concentration, parts
per million by volume as hexane
1. The
flow rate of landfill gas, QLFG, shall be determined by
measuring the total landfill gas flow rate at the common header pipe that leads
to the control device using a gas flow measuring device calibrated according to
the provisions of § 4 of Reference Method 2E of Appendix A of 40 CFR Part
60.
2. The average NMOC
concentration, CNMOC, shall be determined by collecting
and analyzing landfill gas sampled from the common header pipe before the gas
moving or condensate removal equipment using the procedures in Reference Method
25C or Reference Method 18 of Appendix A of 40 CFR Part 60. If using Reference
Method 18 of Appendix A of 40 CFR Part 60, the minimum list of compounds to be
tested shall be those published in the "Compilation of Air Pollutant Emission
Factors (AP-42)" (see 9VAC5-20-21). The sample location on the common header
pipe shall be before any condensate removal or other gas refining units. The
owner shall divide the NMOC concentration from Reference Method 25C of Appendix
A of 40 CFR Part 60 by six to convert from CNMOC as
carbon to CNMOC as hexane.
3. The owner may use an alternative method to
determine landfill gas flow rate and NMOC concentration if the method has been
approved by the board.
D.
When calculating emissions for prevention of significant deterioration
purposes, the owner of each MSW landfill subject to the provisions of this
article shall estimate the NMOC emission rate for comparison to the prevention
of significant deterioration major source and significance levels in Article 8
(9VAC5-80-1700 et seq.) of Part II of 9VAC5 Chapter 80 using the "Compilation
of Air Pollutant Emission Factors (AP-42)" (see 9VAC5-20-21) or other
measurement procedures acceptable to the board. If a collection system, which
complies with the provisions in 9VAC5-40-5820 C 2 is already installed, the
owner shall estimate the NMOC emission rate using the procedures provided in
subsection C of this section.
E.
For the compliance test required in 9VAC5-40-5820 C 2 c (2), Reference Method
25 or Reference Method 18 of Appendix A of 40 CFR Part 60 shall be used to
determine compliance with 98 weight-percent efficiency or the 20 ppmv outlet
concentration level, unless an alternative method to demonstrate compliance has
been approved by the board as provided by 9VAC5-40-5820 C 2 a (2). If using
Reference Method 18 of Appendix A of 40 CFR Part 60, the minimum list of
compounds to be tested shall be those published in the "Compilation of Air
Pollutant Emission Factors (AP-42)" (see 9VAC5-20-21). The following equation
shall be used to calculate efficiency:
Control Efficiency = (NMOCin -
NMOCout)/(NMOCin)
where
NMOCin = mass of NMOC entering
control device
NMOCout = mass of NMOC exiting
control device
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.
