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Case Study Spend Now To Save Later: Evaluating Water Treatment Systems Over The Long-Term Analyzing The Costs Of A New Water Treatment Installation by Bruce Scholten S tricter government regulations combined with shrinking operating budgets means that many municipalities are struggling to install or upgrade water and wastewater systems. But even with limited funds, water treatment is a smart long-term investment, and one that can yield economic benefits quickly. In order to make an accurate cost evaluation — and the best water treatment system choice — municipalities should consider installation costs and long-term lifecycle costs, including operating labor, media and chemical usage, and waste handling. The Challenge: Pure Water For A Thirsty California Valley In 2007, a desert community's water district in southern California faced a growing water crisis. Serving approximately 30,000 people, this water district had a single supply source, a local groundwater aquifer. In recent years, their water demand had increased, exceeding the natural recharge to the groundwater basin. As a result, the valley was experiencing chronic downward trending of usable water. The water district began researching options that would ensure its ability to meet present and future water needs for the over 12,000 valley homes and 20 businesses. Purchasing water from the metropolitan water district (MWD) would be costly in this water- constrained high-desert environment, and was incompatible with its mandate of delivering the highest quality water at the best possible price to the local community while ensuring self-sustaining water resources. MWD Full Service Treated Volumetric Cost ($/acre foot) According to the American Water Works Association, the average United States domestic indoor per capita water use is approximately 70 gallons/day (drinktap.org). This means the 30,000 people in the Valley consume approximately 2.1 million gallons of water every day simply for indoor domestic use (not including outdoor domestic, agricultural, or industrial water, all of which could be significant). At an average California wholesale cost of $794/(acre foot)(Tier1) according to MWD, the cost to purchase enough water to satisfy just its current water needs would be approximately $8,700/day, or $3.2 million the first year. Furthermore, over the past decade, MWD has averaged a 7.3% price increase per year. Projecting a similar price increase for the next 20 years and calculating the net present value (NPV) of those costs results in a projection of $68 million just to meet this community's current demand for water. Tier 1 Supply Rate: recovers the cost of maintaining a reliable amount of supply. Tier 2 Supply Rate: set at MWD's cost of developing additional supply to encourage efficient use of local resources. Water Online The Magazine, Cleanwater Edition ■ wateronline.com With this bench- mark in hand, the