Q330. If a natural gas common pipe is connected to a series of small combustion units and a subpart D unit, how should emissions be reported?

A330. As described in 40 CFR 98.36(c)(3), the common pipe reporting configuration may be used for the small combustion units.  If a portion of the fuel serving a common pipe is diverted to a flare, another stationary fuel combustion unit (or units), a chemical or industrial process, or a Part 75 unit (Subpart D or 98.33(a)(5)), company records may be used to subtract out the diverted fuel stream from the fuel served to the units in the common pipe configuration.  The emission reporting for the subpart D unit would be unaffected by how the emissions are calculated for the common pipe configuration.