40 C.F.R. § Table W-1A to Subpart W of Part 98
Table W-1A to Subpart W of Part 98-Default Whole Gas Emission Factors for Onshore Petroleum and Natural Gas Production Facilities and Onshore Petroleum and Natural Gas Gathering and Boosting Facilities
| Onshore petroleum and natural gas production and Onshore petroleum and natural gas gathering and boosting | Emission factor (scf/hour/component) |
| Eastern U.S. | |
| Population Emission Factors-All Components, Gas Service1 | |
| Valve | 0.027 |
| Connector | 0.003 |
| Open-ended Line | 0.061 |
| Pressure Relief Valve | 0.040 |
| Low Continuous Bleed Pneumatic Device Vents2 | 1.39 |
| High Continuous Bleed Pneumatic Device Vents2 | 37.3 |
| Intermittent Bleed Pneumatic Device Vents2 | 13.5 |
| Pneumatic Pumps3 | 13.3 |
| Population Emission Factors-All Components, Light Crude Service4 | |
| Valve | 0.05 |
| Flange | 0.003 |
| Connector | 0.007 |
| Open-ended Line | 0.05 |
| Pump | 0.01 |
| Other5 | 0.30 |
| Population Emission Factors-All Components, Heavy Crude Service6 | |
| Valve | 0.0005 |
| Flange | 0.0009 |
| Connector (other) | 0.0003 |
| Open-ended Line | 0.006 |
| Other5 | 0.003 |
| Population Emission Factors-Gathering Pipelines, by Material Type7 | |
| Protected Steel | 0.47 |
| Unprotected Steel | 16.59 |
| Plastic/Composite | 2.50 |
| Cast Iron | 27.60 |
| Western U.S. | |
| Population Emission Factors-All Components, Gas Service1 | |
| Valve | 0.121 |
| Connector | 0.017 |
| Open-ended Line | 0.031 |
| Pressure Relief Valve | 0.193 |
| Low Continuous Bleed Pneumatic Device Vents2 | 1.39 |
| High Continuous Bleed Pneumatic Device Vents2 | 37.3 |
| Intermittent Bleed Pneumatic Device Vents2 | 13.5 |
| Pneumatic Pumps3 | 13.3 |
| Population Emission Factors-All Components, Light Crude Service4 | |
| Valve | 0.05 |
| Flange | 0.003 |
| Connector (other) | 0.007 |
| Open-ended Line | 0.05 |
| Pump | 0.01 |
| Other5 | 0.30 |
| Population Emission Factors-All Components, Heavy Crude Service6 | |
| Valve | 0.0005 |
| Flange | 0.0009 |
| Connector (other) | 0.0003 |
| Open-ended Line | 0.006 |
| Other5 | 0.003 |
| Population Emission Factors-Gathering Pipelines by Material Type7 | |
| Protected Steel | 0.47 |
| Unprotected Steel | 16.59 |
| Plastic/Composite | 2.50 |
| Cast Iron | 27.60 |
1 For multi-phase flow that includes gas, use the gas service emissions factors.
2 Emission Factor is in units of "scf/hour/device."
3 Emission Factor is in units of "scf/hour/pump."
4 Hydrocarbon liquids greater than or equal to 20°API are considered "light crude."
5 "Others" category includes instruments, loading arms, pressure relief valves, stuffing boxes, compressor seals, dump lever arms, and vents.
6 Hydrocarbon liquids less than 20°API are considered "heavy crude."
7 Emission factors are in units of "scf/hour/mile of pipeline."
40 C.F.R. §Table W-1A to Subpart W of Part 98