Frequently Asked Questions
To help provide a solid foundation for solutions that can help sustain our natural resources, water reuse and desalination facts and terminology have been provided. By understanding the facts and the terminology along with the existing misconceptions, one can begin to understand the needs and benefits of
water reuse and desalination.
- During the most recent drought, was there an additional cost to the District to import more water?
Yes. The law of supply and demand affects imported water prices. Available imported water for the District can drop to as low as 5% (or less) for normal supplies from the State Water Project. The District then must pay high on-the-spot market prices to make up the difference.
- What is the cost of purified water per gallon?
The normalized production cost of water from the SVAWPC is less than a penny ($.005) per gallon.
- What is the cost comparison between operating a seawater desalination plant, Silicon Valley Advanced Water Purification Center and imported water?
The cost of imported water varies during years of drought and allocation from the State Water Board. The vulnerability of imported water to drought and environmental regulation has been repeatedly shown, which is why purified is a safe and reliable source for our future water supply. On an annual basis, the purification center costs $3.6-$5.5 million to operate and produce 8 million gallons of purified water per day (MGD). A desalination plant, which purifies seawater to produce drinking water, can cost anywhere from $11.2- $17.6 million dollars per year to operate and produce 8 MGD. In terms of energy usage, the pressure needed to run the reverse osmosis feed pumps is 190 pounds per square inch when purifying reused water. Desalination requires the pressure to be increased to 900-5,000 pounds per square inch, which significantly increases the energy usage and costs.
- How much would expansion of purified water cost in Santa Clara County?
The district is still in the very early planning process for potable reuse and does not know yet the full costs. It is important to keep in mind that an expansion project like this will include expansion of the purification facility from 8 MGD to 32 MGD, building new pipelines to transport the water to groundwater basins, and associated infrastructure. Overall, the current cost estimate for this program, which includes the five different construction projects, is estimated to cost $1 billion.