Comment submitted by Andrew D. Shroads, QEP, SC&A, Inc.

§98.233(i)(3) contains two equations. Equation W-14A has an error with the purge factor that causes the equation to yield erroneous results. The equation subtracts a "purge factor" from the volume of the item being evacuated of natural gas (i.e., blowdown), converted to standard cubic feet. The "purge factor" is either 0, if a non-GHG gas is used to purge the item, or 1 if the item is not purged. Since the volume being purged is converted from actual cubic feet to standard cubic feet, inconsistent units are being subtracted, (i.e. standard cubic feet purged and actual cubic feet "purge factor"). This also results in a negative number if the volume of the purged item in standard cubic feet is less than in actual cubic feet, (i.e. actual conditions are hotter or a lower pressure than standard conditions). Additionally, the "purge factor" does not make sense in the way it is described. If the item is not being purged, then the calculation should not be used, as there would be no GHG emissions from the blowdown stack, rather than including it in the calculation.