Amidst Drought, Solar Desalination Allows California Water District To Gain New Access to Fresh Water
California’s Panoche Water District has implemented a solar desalination facility in response to the need for cost-effective solutions that would ensure the availability of sustainable water in the vital agricultural region.
The facility, located in Firebaugh, Calif., utilizes renewable desalination technology from WaterFX.
The water district is deploying WaterFX Aqua4 technology as a remedy for drainage issues that have reached critical levels for the region’s agricultural industry. Irrigated water in the Central Valley contains elevated levels of salinity ranging from 15,000 to more than 40,000 ppm in many regions (greater than the salt content of seawater).
Meanwhile, drought conditions throughout the state have limited access to contracted water delivered from the U.S. Bureau of Reclamation through the Central Valley Project, resulting in water districts receiving only a portion of their allotted water contracts. This year, the projected allocation is expected to fall to zero.
Sustainable water reuse through solar desalination can provide a scalable, alternative source of water unencumbered by the low reliability of imported water and high-energy costs.
After six months in operation, the 6,500-square-foot, solar-powered test facility has produced up to 8 gallons per minute of pure water from saline discharge drainage, and will be expanded to produce 2,200 acre-feet per year.
“We are very encouraged by the results so far and are looking forward to increasing the capacity to provide a treatment solution for larger volumes of drainage water,” says Dennis Falaschi, Panoche Water and Drainage District manager. “Farmers, in partnership with federal agencies, have invested in a solution that may soon solve drainage issues across all of California’s west side.”
The Panoche Water District and Drainage District serves more than 44,000 acres of the Central Valley in and around Firebaugh, Calif., including farmlands growing almonds, tomatoes, melons, asparagus, pistachios and alfalfa. The salinity of drainage water collected through intricate tile systems placed below irrigated crops and pumped to drainage canals necessitates designated reuse acreage that the Panoche District uses for recycling drainage water, growing salt tolerant crops and now employing water treatment technology.
“Panoche is a very forward-thinking water district to begin exploring sustainable, alternative water reuse options and it will greatly benefit local farms,” says Aaron Mandell, WaterFX chairman and founder. “This project represents a dramatic shift in how we use and reuse water in scarce regions like California. Our long term goal is to chart a new course towards water independence and reduce the need to import water from finite natural sources; this will pave the way towards economic growth dependent on water reliability.”
The WaterFX Aqua4 system differs from traditional seawater desalination, which is performed by an electricity intensive reverse-osmosis process that forces salt and other solids through a membrane at high pressure. WaterFX’s Aqua4 system reclaims water using a Concentrated Solar Still (CSS), a new device with advanced solar absorption technology, requiring minimal electricity and fuel input and producing more than 200 acre-feet of freshwater per acre of solar collection area.
Aqua4 consists of a solar thermal collector, an absorption heat pump, a multi-stage distillation system and a thermal storage unit to store solar heat and ensure 24-hour-per-day operation. The system is designed to deliver maximum value from renewable energy inputs and features a modular and moveable design, a compact footprint and the ability to easily scale up or down. High-efficiency thermal evaporation makes the system robust and able to achieve high recovery from a variety of water streams including drainage water, wastewater, produced water and seawater. The Aqua4 system will also reclaim extracted metals and salts, removing them from the water system entirely and eliminating brine discharge.