Nitrogen Mass Balance for Municipal Wastewater

Abstract

Nitrate pollution of ground water is a serious problem in many areas of the United States. One source of nitrate contamination is municipal wastewater effluent. The practice of reusing treated sewage effluent is becoming more prevalent due to limited municipal water supplies. In this study, the discharge and end use of treated effluent in the Phoenix, Ariz., metropolitan area in 1997 were investigated. It was determined that 78% of the total nitrogen in treated wastewater effluent was retained in the local watershed, and 22% was exported from the area in the Gila River. Investigation into the end use of this effluent indicates that increased nitrate contamination of ground water may result from reusing wastewater.