The paper gives an estimate of hazardous air pollutant (HAP) emissions from sewers in a large U.S. city. (NOTE: Such emissions are usually omitted from both volatile organic compound and HAP emission inventories, perhaps from a lack of appreciation for the potential emissions impact and/or inadequate emissions estimation procedures.) An approach was developed and implemented that used EPA's National Pollutant Discharge Effluent System (NPDES) data as the basis for estimating HAP discharges to municipal sewers. The results showed that the sewer HAP emissions are likely to be equal to, or greater than, those from the city's wastewater treatment facilities.

"PB95-174645"--Cover. "EPA 600/A-95-022." Includes bibliographical references (p. 7).

Emissions from municipal sewers are usually omitted from both volatile organic compound and hazardous air pollutant (HAP) emission inventories. This omission may result from a lack of appreciation for the potential emissions impact and/or inadequate emissions estimation procedures. This paper presents results of efforts to estimate HAP emissions from sewers in a large U.S. city. An approach was developed and implemented that used EPA's National Pollutant Discharge Effluent System (NPDES) data as the basis for estimating HAP discharges to municipal sewers. The Collection Organic Release Algorithm (CORAL+) model was used with these data to estimate city-wide HAP emissions from sewers. The results showed that the sewer HAp emissions are likely to be equal to or greater than those from the city's wastewater treatment facilities. The sewer HAP emissions estimate of over 270 megagrams per year (300 tons per year) for the city was expected to underestimate sewer emissions, since sewer effluent wastewater concentration data from NPDES were used to formulate the estimate.