Carbon Footprinting a Full-scale Wastewater Treatment Plant – A Case Study

This paper describes a carbon footprinting study on the American Bottoms Regional Wastewater Treatment Facility (ABWWTF). Plant specific data were gathered to analyze emissions from both direct and indirect sources. In 2010, ABWWTF emitted an estimated 17,396 tons of CO2e (carbon dioxide equivalent), which includes 64% (11,126 tons) from electricity use, 13% (2,303 tons) from lime use, 11% (1,860 tons) from nitrogen removal, 6% (990 tons) from sludge handling, and 4% (744 tons) from BOD removal. The handling of solid wastes and related fuel use (gasoline, diesel, and natural gas) accounted for 2% (373 tons) of total emissions in 2010. ABWWTF could lower its carbon footprint primarily by minimizing electrical consumption through high efficiency motors utilized in its largest pumps and blowers. This case study illustrates how to carbon footprint a full-scale wastewater treatment facility. This work can be expanded to include other emissions such as the fuel use from transporting chemicals to the plant, so carbon footprinting the plant can become more comprehensive and complete.