Method for Estimating and Predicting CO2e Emissions: Case Study of an Urban Wastewater System in Suzhou, China

As a fundamental infrastructure to sustain human activities and development, urban wastewater systems are becoming more and more important in the context of population growth and business expansion. It is important to analyze and assess environmental impacts of these systems to community development. This paper presents a model developed for estimating carbon dioxide equivalent (CO2e) emissions resulting from urban wastewater systems addressing both construction and operational activities. Construction emissions are divided into three categories: material manufacture, material transportation, and pipe installation. Operational emissions include the following: energy consumption–related emissions and wastewater treatment–related emissions. Emission factors of gasoline, diesel oil, and electricity were calculated. The model was demonstrated by applying it to the wastewater system in the city of Suzhou, China, to quantify CO2e emissions for the period of 2005–2010. The results highlight the high prop...