What do you do when you have a thirsty nuclear plant in the desert near a couple of cities that are strapped for cash? Sell treated sewage from the waste water plant to the nuclear plant for use in its cooling towers.
In Arizona, a group of 5 desert cities including Glendale, Scottsdale, Mesa, Phoenix, and Tempe have recently signed an agreement to supply effluent water from a nearby waste water treatment plant to the Palo Verde Nuclear Power Plant for the next 40 years. The new deal renews an older agreement and helps the city to raise money while helping the nuclear plant secure license renewal from the NRC.
Effluent Water
Effluent water is the discharge of a waste water treatment plant. The plants take in raw sewage and remove the physical, chemical, and biological contaminants found in runoff and domestic waste water. While effluent water is considerably cleaner than the raw sewage that enters the plant, it’s still not suitable for drinking or use in the household. Many waste water plants simply discharge effluent water back into the river or lake nearby. However in recent years, many municipalities are recognizing the value in effluent water previously considered an environmental burden.
The New Deal
Under this new deal, Palo Verde will pay $30 million over the next 4 years to upgrade the aging 91st Avenue Waste Water Treatment Plant which supplies the effluent water. The 91st avenue plant pipes treated sewage 36 miles to Palo Verde. Once there, the water is used in the cooling towers and is eventually evaporated into the atmosphere.
Higher Price for Effluent
Currently Palo Verde pays $53 per acre-foot (about 326,000 gallons). The new deal will allow the cities to raise the price of the effluent water by 10.5% annually and will eventually reach $300 per acre foot. Palo Verde plans to offset the increase in price with water saving efficiency improvements to the cooling towers and by reducing operating costs through upgrades elsewhere in the plant.
Free Up Excess Water
In addition to raising the price of the water, the deal also allows the city to sell more effluent water elsewhere. The previous deal required the cities to set aside 105,000 acre-feet (about 34 billion gallons) per year for Palo Verde. Even though the plant uses considerably less water than this the cities must still keep that water available under the terms of the contract. The new contract calls for 80,000 acre-feet which will allow the cities to sell the remaining 25,000 acre-feet as irrigation water for golf courses and other areas.
Win-Win Situation
The win-win deal comes at the perfect time as Palo Verde plans to apply to the NRC to renew its operating license for another 20 years. Having secured a water supply in a desert area will help the station with this process by reducing the administrative burden of environmental studies associated with finding another source of water. The deal also helps the cities to close gaps in the budget by increasing the price on some of the water and selling the rest elsewhere.
Widely considered a waste product, effluent water is becoming increasingly valuable in areas strapped for water, cash, or looking to reduce environmental footprint. The Palo Verde situation has already attracted the attention of Florida Power and Light which will use effluent water for the new reactors it plans to build at the Turkey Point nuclear plant.
Image Credit
Water Treatment Plant courtesy of Flickr user IMCA Photos under the CC license.
2 Comments
The first thing that really popped out at me was the yearly increases in water costs: 10.5% !!! Until it costs six times what it does now!! For something they’d otherwise throw away?
If that’s not a sign of how economically viable nuclear power is, I can’t think of one. Imagine doing this to a coal plant, or a natural gas plant, and see what happens. They’d go belly up instantly. But do it to a plant with low operating costs, forty years of paying off the construction costs, and they just keep going.
Thanks for sharing this excellent information!