In response to increased emphasis on sustainability and the reduction of carbon/greenhouse gas (GHG) emissions, The District of Columbia Water and Sewer Authority (DCWASA) and its program managers have developed comparisons of options intended to lower the AWTP’s GHG inventory (also called “carbon footprint”). These comparisons have used different assumptions as tothe carbon density of various functions (electricity, chemical and fuel use). This paper details a recommended first step for all utilities and the results of that effort: development of a utility-wide GHG inventory for DCWASA.
This paper summarizes the DCWASA utility-wide GHG inventory that was developed in conformance with the Climate Registry’s General Reporting Protocol (Climate Registry, 2008). The inventory is being prepared for a subsequent audit in preparation for potential certification by the Climate Registry. The completed audit would serve to “ratify” the criteria assumptions and magnitude determinations while providing context for all future DCWASA-specific GHG evaluations. The audited inventory further arms the utility with knowledge, allowing appropriate responses to GHG or carbon cap-and-trade regulation. The relative contributions of DCWASA’s wastewater treatment, wastewater conveyance, water distribution, and fleet/support operations will be discussed herein as well as the inventory’s sensitivity to various key assumptions.