Q389. Within e-GGRT, how would a landfill handle multiple destruction devices including a portion of the gas sent off-site for destruction? Is there a way to add multiple on-site destruction devices for a gas system?

A389. e-GGRT does not collect data for individual destruction devices. e-GGRT does ask if destruction occurs at the facility, off-site, or both. All reporting in e-GGRT for landfills is done at the facility level.

The following is provided to assist in performing the calculations and reporting certain elements when several destruction devices are used routinely. e-GGRT provides a means to indicate if a back-up destruction device is used; this is not what is being considered here as multiple destruction devices. Two basic scenarios are considered: 1) flow and methane content are measured at a single central location and the gas is then piped to different destruction devices (either all on-site or on-site and off-site), but the flow rate per device is not measured; 2) flow and methane content are measured separately for each on-site destruction device and, if applicable, gas sent off-site for destruction. Further information can be found via the e-GGRT Help link in the left-hand margin of e-GGRT. Go to Using Subpart HH Calculation Spreadsheets and then to Using the Equation HH-6, HH-7, and HH-8 Calculation Spreadsheet.

Scenario 1, Central measurement location.
Determine single value of R directly from measurement data using Equation HH-4.
Determine single value for DE using the average destruction efficiency of all destruction devices.
Determine f_Dest as the average annual hours for which the routinely used destruction devices were operated divided by the hours the collection system operated (presumably 8760 hour); see equation below.
Determine single value for CE using Table HH-3 considering the entire landfill facility.
Determine a single value of f_Rec based on the annual operating hours of the collection system.
Equations HH-5 through HH-8 can be used directly given the parameters determined above.
Other e-GGRT reporting parameters (annual volume of gas, annual average methane concentration and number of days/week missing data procedure were used) are straight forward under this scenario.

Scenario 2, Measurement at different locations.
Determine a value of R using Equation HH-4 for each destruction device (monitoring location).
Determine a value of DE for each destruction device
Determine a value of f_Dest for each destruction device based on the annual hours for which the specific destruction device was operating divided by the number of hours flow was sent to the destruction device (or the annual hours the collection system operated that is associated with that destruction device)
Determine single value for CE using Table HH-3 considering the entire landfill facility.
If separate gas collection systems are operated for different destruction devices, determine a value of f_Rec for each destruction device-specific gas collection system; otherwise, determine a single value of f_Rec based on the annual operating hours of the collection system.
Calculations for Equation HH-5 are not dependent on destruction devices; the equations below can be used to determine the reporting quantities for Equations HH-6 through HH-8.
Report annual volume of gas as the cumulative volume of gas collected across all measurement locations.
Report the annual average CH4 concentration as the direct arithmetic average of the measured concentrations across all measurement locations (do not use a flow weighted average concentration).
Report the missing data times as the cumulative number of instances that missing data procedures were used across all measurement locations. [Note that currently the system only allows you to report missing concentration data on a daily or weekly basis. We will be modifying the system to allow an entry for both daily and weekly in the case that CH4 concentration is monitored daily for certain destruction devices and weekly for others (or for gas sent off-site).]

Calculate CH4 generation and CH4 emissions using measured CH4 recovery and estimated gas collection efficiency and Equations HH-7 and HH-8 of section 98.343(c)(3)(ii).