Emissions of VOCs from a Municipal Sewer

Abstract

Abstract In response to increasing regulatory scrutiny related to sources of hazardous air pollutants and reactive organic gases, several recent studies have addressed the characterization and control of volatile organic compound (VOC) emissions from municipal and industrial wastewater treatment plants. VOC emissions from wastewater collection systems have received much less attention. A naturally well-ventilated municipal sewer interceptor that receives significant quantities of VOC-laden industrial wastewater was studied to quantify VOC emissions. Headspace outgassing rates, when summed across four manhole covers, were as high as 2300 m3/h, far exceeding headspace turnover rates previously estimated and published in the technical literature. Individual concentrations of five target VOCs (benzene, toluene, ethylbenzene, total xylenes, and tetrachloroethene) in the sewer headspace ranged from 0 to 46 ppm during three daytime monitoring events and one 24-hour event. Emissions were greatest for toluene, app...