Virginia Law

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:

Q_M = 2L₀R(e^-kc - e^-kt)

where

Q_M = 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:

where

Q_M = 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

M_i = mass of solid waste in the i^th section, megagrams

t_i = age of the i^th 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.