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.

This page provides an overview of the Subpart W blowdown vent stacks source category reporting requirements.

The blowdown vent stacks source category is applicable to Onshore Natural Gas Processing, Onshore Natural Gas Transmission Compression, and LNG Import and Export Equipment.

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

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

If the facility has the source type, the Best Available Monitoring Methods and Missing Data table must be completed.

• For further information, see Best Available Monitoring Methods and Missing Data Reporting.

Reporting Requirements

For all unique volumes that are blown down once during the year, the facility must report:

• Total number of blowdowns for all unique physical volumes (98.236(c)(7)(ii)(A))
• Annual total CO₂ emissions from all unique physical volumes as an aggregate per facility (98.236(c)(7)(ii)(B))
• Annual total CH₄ emissions from all unique physical volumes as an aggregate per facility (98.236(c)(7)(ii)(B))

For each unique physical volume that is blown down more than once during the calendar year, the facility must report:

• Unique name or ID for the unique physical volume (98.236(c)(7)(i)(C))
• Which equation was used to calculate natural gas venting emissions? (W-14A or W-14B)
• Total number of blowdowns for each unique physical volume in the calendar year (98.236(c)(7)(i)(A))
• Annual total CO₂ emission for each unique physical blowdown volume (98.236(c)(7)(i)(B))
• Annual total CH₄ emission for each unique physical blowdown volume (98.236(c)(7)(i)(B))

Total Emissions

The total emissions roll-up at the top of the sheet reflects the sum of the CO₂ equivalents of each gas emission reported for the source type.  These summations are reflected and aggregated on the Introduction tab.