An overview of the pooled emission estimation program (peep) for potws

California Air Toxics “Hot Spots” Information and Assessment Act of 1987 (AB 2588) establishes a program to develop statewide inventory of site-specific air toxic emissions of over 500 compounds. The goals of AB 2588 are to collect emissions data, to identify facilities having localized impact, to ascertain health risks, and to notify nearby residents. Twenty-four agencies with Publicily Owned Treatment Works (POTWs) initiated a voluntary Pooled Emission Estimation Program (PEEP) at 21 facilities for 18 unit processes. For majority of the unit processes, tests were conducted at three different facilities during each round. The target compounds were selected 21 volatile organic compounds (VOCs), formaldehyde and 2, 4, 6 trichlorophenol. The program collected and analyzed approximately 2060 air samples and 1220 liquid samples to develop emission factors. A QA/QC project plan which included field and laboratory elements were developed and implemented to ensure high quality data. Discussions on the data evaluation procedures, development of emission factors (the ration of the compound released to the air per total quantity of the compound entering a unit process), estimating VOC emissions from a weir using DO measurements, and an emission factor model for estimating air emissions using liquid/sludge VOC concentrations for liquid, sludge and digester gas handling treatment facilities as listed above are provided.