DEQ Issues Draft Guidance for Calculating Tank Truck Loading Losses

DEQ recently issued a draft guidance document to address condensate and crude oil loading losses from tank trucks calculated using AP-42, Section 5.2. The main purpose of the guidance is to address the percent reduction that can be applied to these estimates in order to account for the VOC content of the vapors generated during the loading process. In summary, DEQ determined that applicants may assume the VOC content of loading vapors to be 85% by weight for crude oil (API gravity less than 50°) prior to custody transfer, provided that the calculated emissions factor is greater than the default AP-42 factor (2 lb/mgal). All other petroleum liquids should be assumed to have a VOC content of 100% in the vapor. The guidance also addresses other assumptions that can be made for these calculations in order to better standardize how industry estimates these emissions. Comments must be provided by April 21, 2017, and the complete guidance document may be found here.