EPA Greenhouse Gas Reporting – Subpart W Fugitive methane emissions John Erickson, PE

1. the voice and choice of public gas EPA Greenhouse Gas Reporting – Subpart W Fugitive methane emissions John Erickson, PE American Public Gas Association

2. Purpose of this Webinar • Summarize the fugitive emission estimating requirements of the rule • Demonstrate how to use the APGA EXCEL spreadsheet calculator to determine if you are required to report under Subpart W

3. Why Fugitive Methane? • EPA believes that methane, the primary component of natural gas, is a greenhouse gas ~ 21 times more effective than carbon dioxide • EPA wants an inventory of all greenhouse gas emissions • No reductions are mandated at this time

4. Reporting • First reports are due March 30, 2012 for estimated emissions for calendar year 2011 • Reporting is on-line via the EPA’s E-GGRT system • Utilities with estimated fugitive emissions plus combustion emissions over 25 thousand metric tons CO2 equivalent must report • Estimates must be based on EPA’s emission factors, not actual emissions

5. What to Report • # of leaking meters, regulators, and associated equipment at above grade transmission-distribution transfer stations, including equipment leaks from connectors, block valves, control valves, pressure relief valves, orifice meters, regulators, and open ended lines.

6. What to Report • Estimated emissions from: • Below grade transmission-distribution transfer stations. • Above grade metering-regulating station. • Below grade metering-regulating stations. • Mains • Services • Complete list found at 98.236(a)(16) of the rule

7. What to Report • Also report under subpart W of this part the emissions of CO2, CH4, and N2O from stationary fuel combustion sources following the methods in §98.233(z). • (z)(3) External fuel combustion sources with a rated heat capacity equal to or less than 5 mmBtu/hr do not need to report combustion emissions or include these emissions for threshold determination in §98.231(a).

8. 98.233(z) Methods • CO2 = scf *0.001028 mmbtu/scf * 53.02 kgCO2/mmbtu * 0.001mt/kg • CH4 = scf * mmbtu/scf * 0.001 kg CH4/mmbtu * 0.001 mt/kg * 21 mt CO2e/mtCH4 • N2O = scf * mmbtu/scf * 0.0001 kgN2O/mmbtu * 0.001 mt/kg * 310 mtCO2e/mt N2O

9. Annual Leak Surveys Required • At least once each year, check “TD transfer station” components for leaks • “Transmission-distribution (TD) transfer station means a meter-regulating station where a local distribution company takes part or all of the natural gas from a transmission pipeline and puts it into a distribution pipeline.” • This is the only actual measurement required for fugitive methane from distribution systems

10. Important Definitions • “Natural gas distribution means the distribution pipelines and metering and regulating equipment at metering- regulating city gate stations, and excluding customer meters, that physically deliver natural gas to end users and that are operated by a Local Distribution Company (LDC) within a single state.” • “Metering-regulating station means a station that meters the flowrate, regulates the pressure, or both, of natural gas in a natural gas distribution facility. This does not include customer meters, customer regulators, or farm taps.”

11. What is a leak? • Measurement means determining, yes or no, if the equipment is leaking, not the volume of gas leaking • 98.234 (a)(2) Method 21. Use the equipment leak detection methods in 40 CFR part 60, appendix A-7, Method 21. If using Method 21 monitoring, if an instrument reading of 10,000 ppm or greater is measured, a leak is detected. • Method 21 includes HFI, CGI, etc.

12. Example: Springfield, MO • 5 TD Gate stations (owns meter runs at 1) • 31 BG M&R Stations 100-300 psig inlet • 81 BG M&R stations < 100 psig inlet • Mains: • 418.69 miles protected steel • 838.57 miles plastic • Services: • 13,951 protected steel • 62681 plastic

13. Leaker Emission Factors • Above Grade Transmission/distribution transfer stations • Connector = 1.72 cf/hr/count • Block Valve = 0.566 cf/hr/count • Control Valve = 9.48 cf/hr/count • Pressure Relief Valve = 0.274 cf/hr/count • Orifice Meter = 0.215 cf/hr/count • Regulator = 0.784 cf/hr/count • Open-ended Line = 26.533 cf/hr/count

14. Leaker Emission Factors • “If one leak detection survey is conducted, assume the component was leaking for the entire calendar year. • If multiple leak detection surveys are conducted, assume that the component found to be leaking has been leaking since the previous survey or the beginning of the calendar year. • For the last leak detection survey in the calendar year, assume that all leaking components continue to leak until the end of the calendar year.”

15. Leaker vs Population Factor • Leaker emission factor applies only to equipment found to be leaking • Population emission factors apply to the total count of the type of equipment regardless of whether or not it is actually leaking

16. Population Emission Factors - • Distribution Mains • Unprotected Steel = 12.77 cf/hr/mile • Protected Steel = 0.36 cf/hr/mile • Plastic = 1.15 cf/hr/mile • Cast Iron = 27.67 cf/hr/mile

17. Population Emission Factors - • Distribution Service lines • Unprotected Steel = 0.19 cf/hr/service • Protected Steel = 0.02 cf/hr/service • Plastic = 0.001 cf/hr/service • Copper = 0.03 cf/hr/service

18. Population Emission Factors • Below Grade Metering-Regulating station • Inlet Pressure > 300 psig = 1.32 cf/hr/station • Inlet Pressure 100-300 psig = 0.20 cf/hr/station • Inlet Pressure < 100psig = 0.10 cf/hr/station

19. Population Emission Factors • For above grade meter-regulator stations, the population emission factor is the average calculated hourly emission rate per meter/regulator run at TD Transfer stations • EF = Sum (Es,i/8760/Count) (Eq. W-32) • Es,i = Annual volumetric GHG emissions at standard condition from all equipment leak sources at all above grade TD transfer stations, and • Count = Total number of meter/regulator runs at all above grade TD transfer stations.

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