This page provides an overview of the Subpart W reporting requirements for the transmission tanks source type.

Please see Reporting Form Instructions on downloading the blank reporting form and uploading the completed reporting form.

You may also refer to Optional Calculation Spreadsheet Instructions to download the Subpart W calculation spreadsheet.

 

The transmission tanks source type is applicable to Onshore natural gas transmission compression facilities [98.230(a)(4)].

Indicate if the facility has the source type via the radio buttons.

If the source type is present you must report the required elements.

If the facility has the source type, then indicate whether missing data procedures were used. 

Reporting Requirements

Table K.1 Transmission tank emissions must be completed for each vent stack. Required data elements include:

• Unique Name or ID number for the transmission storage tank vent stack [98.236(k)(1)(i)]
• Method used to determine if dump valve leakage occurred [98.236(k)(1)(ii)]
• Did dump valve leakage occur? [98.236(k)(1)(iii)]
• Was there a flare attached to the transmission storage tank vent? [98.236(k)(1)(iv)]
• Dump valve leakage directly to atmosphere

  • Did scrubber valve leakage occur while the vent stack was vented directly to the atmosphere? [98.236(k)(2)]

  • Method used to measure leak rate [98.236(k)(2)(i)] 

  • Measured leak rate (standard cubic feet/hour) [98.236(k)(2)(ii)]

  • Duration of time leak is counted as having occurred (vented to atmosphere) (hours) [98.236(k)(2)(iii)]

  • CO₂ emissions from venting gas directly to the atmosphere (mt CO₂) [98.236(k)(2)(iv)]
  • CH₄ emissions from venting gas directly to the atmosphere (mt CH₄) [98.236(k)(2)(v)]

• Flared dump valve leakage

  • Did scrubber valve leakage occur while the vent stack was vented to a flare? [98.236(k)(3)]

  • Method used to measure leak rate [98.236(k)(3)(i)]

  • Measured leak rate (standard cubic feet/hour) [98.236(k)(3)(ii)]
  • Duration of time that flaring occurred (hours) [98.236(k)(3)(iii)]
  • CO₂ emissions from flaring gas (mt CO₂) [98.236(k)(3)(iv)]
  • CH₄ emissions from flaring gas (mt CH₄) [98.236(k)(3)(v)]
  • N₂O emissions from flaring gas (mt N₂O) [98.236(k)(3)(vi)]

Table K.1 Transmission tank emissions

Enlarged View for Table K.1 Transmission tank emissions

Enlarged View for Table K.1 Transmission tank emissions (continued)

Enlarged View for Table K.1 Transmission tank emissions (continued)

Table K.2 Missing data procedures used for Transmission Tanks emission calculations is required for the identification of missing data procedures used for emission calculations. These data elements include:

• Unique Name or ID number for the vent stack [98.236(k)(1)(i)]

• Parameters

• Measurement Frequency

• Number of quarters missing data procedures were used [98.236(bb)(1)] (required only if the measurement frequency was quarterly)

• Total number of hours in the year missing data procedure was used [98.3(c)(8)], [98.236(bb)(2)] (required unless the measurement frequency was quarterly, annually, biannually, or N/A)
• Procedures used to determine missing data [98.235(h)]

Table K.2 Missing data procedures used for Transmission Tanks emission calculations

Total Emissions

The total emissions roll-up at the top of the sheet reflects the sum of each gas emission reported for the source type. These summations are calculated automatically by the Smart Form and tabulated on the Introduction tab.