Incorporating Environmental Impact in Decision Making for Municipal Drinking Water Distribution Systems through Eco-Efficiency Analysis

Municipal water distribution systems have impacts on the environment that are not typically considered. For example, energy consumption for pumping pollutes the air through fossil fuel burning. 7% of the world's energy consumption in 2000 was used to pump and treat water for urban residents and industry. Electricity consumption was about 30 billion kWh for the year 2000. This is expected to reach about 36 billion kWh by the year 2020 and 46 billion kWh by the year 2050 with subsequent increases in environmental burdens due to the production of electricity necessary to treat the water properly. The magnitude of these impacts depends directly on the fuel mix at generating facilities (e.g., fossil, nuclear, hydro, solar, wind, biomass). In addition to energy consumption, the minimization of material use reduces the environmental impact, since any material used (PVC or iron for pipes and concrete and steel for tanks) pollutes the environment during the manufacturing process. The paper presented here will discuss an analysis technique called Eco-Efficiency Analysis that allows for the quantification of environmental impacts to allow decision makers to incorporate environmental impacts in their decisions, thereby reducing the environmental burden they impose on the earth.