Cost Considerations
of the 450-650 Mineral Blend Decision

Water Rates

Customer's monthly water bills will increase over the next 10 years, just as prices for many things will likely rise. Tucson Water estimates that by 2015 the average residential customer's monthly water bill will have increased from today's $19.00 to about $26.00. Power, maintenance costs, and construction of new facilities to utilize all of our renewable Colorado River water will be the major factors in these costs. Tucson Water is asking its customers whether or not they want to make an additional investment in the aesthetic character of our water supply by building a treatment plant to keep the mineral level at 450 by removing the minerals from a portion of the blended water.

Cost of the 650 Blend

If we decide to allow our blended water to rise to the 650 mineral level, there would be no need to construct a reverse osmosis plant and no additional increase in the average monthly water bills above the already anticipated increase to about $26.00 per month. However, as the mineral level increases over time and reaches 650 in about 2020, additional household maintenance will be required due to higher mineral content in water in the home. Although many of these costs may only occur once every few years, the average cost over time may be about $3.00 to $4.00 per month, including items such as shortened life for household appliances like hot water heaters and cooler pads, and the need to purchase additional soap, detergent and household cleansers.

Cost of the 450 Blend

The investment in constructing and operating a reverse osmosis plant to maintain our water at a 450 mineral level would cause an additional increase in the average monthly water bill beginning in 2008. By 2015, when the reverse osmosis plant is completed and operating, this additional cost will reach about $7.00 per month, making the average customer's water bill about $33.00 per month. The plant would begin operation in about 2012.