Desalination began to lose its urgency among Californians and their public officials two years ago, after the drought-busting winter of 2016-17, when heavy rain and snow ended dry conditions in most of the state. The idea of drawing potable water from the sea became even less of a priority this year, when an autumn of record-level fires gave way to one of the state’s wettest winters on record. Reservoirs are brimming. Instead of desperately seeking new sources of water, Californians were moaning about the billions of excess gallons that washed into the Pacific Ocean and the San Francisco Bay. Depleted aquifers began their path to replenishment, too, with snow levels in the water-producing Sierra Nevada Mountains far above normal.
As populations boom and chronic droughts persist, coastal cities like Carlsbad in Southern California have increasingly turned to ocean desalination to supplement a dwindling fresh water supply. Now scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) investigating how to make desalination less expensive have hit on promising design rules for making so-called “thermally responsive” ionic liquids to separate water from salt. Ionic liquids are a liquid salt that binds to water, making them useful in forward osmosis to separate contaminants from water.
The Sweetwater Authority Governing Board was presented with the Southwest Membrane Operators Association (SWMOA) ‘Best Tasting Membrane Water in the Southwest Region Award’ at its July 24 board meeting.
The award recognizes the Authority’s Richard A. Reynolds Desalination Facility as the winner of the Best Tasting Membrane Water Competition held during the SWMOA Annual Symposium in June.
The winning water sample was taken directly from the Richard A. Reynolds Desalination Facility, the same water provided to its customers. Judges based their assessment on the following criteria: taste, odor, color, clarity, mouthfeel, and aftertaste.
Among the participants in the competition representing water agencies from the Southwest United States, the Authority received the highest cumulative score.
Facility provides Authority customers with one-third of their annual water supply
The Richard A. Reynolds Desalination Facility in Chula Vista is a state-of-the-art groundwater desalination facility designed to use reverse-osmosis membrane treatment to remove dissolved salts and microscopic particles, such as bacteria and other contaminants which can be found in groundwater. The facility can produce up to 10 million gallons of drinking water per day, enough for approximately 18,000 families, and provides Authority customers with about one-third of their annual water supply.
The facility began operating in 1999 drawing brackish groundwater from five wells. That same year, the facility was honored with a San Diego Orchid award in the competition’s environmental solutions category. Its phase two expansion was completed in 2017.
The facility’s sustainable design also includes 2,950 ground-mounted solar PV panels as an alternative energy source. The solar array offsets the cost of treating water and reduces the facility’s overall carbon footprint.
The facility was previously honored with the American Society of Civil Engineers’ Project of the Year award, as well as the South County Economic Development Council’s Corky McMillin/Best of South County Award.
The Southwest Membrane Operator Association is an affiliate of the American Membrane Technology Association and dedicated to the Southwest United States region including, but not limited to Arizona, California, Colorado, Hawaii, New Mexico, Nevada, and Utah.
The small South Coast Water District has taken key steps toward construction of a $110 million desalination plant, but the agency faces growing questions of whether it’s in over its head for the ambitious project to be built near Doheny State Beach. The project’s ocean-friendly technology has won praise from the same environmentalists fighting a desalter plant proposed by Poseidon Water for Huntington Beach, one of several things that distinguish the south county plant from the more controversial project to the north.
There is an obvious connection between the proposed multibillion-dollar Sacramento Delta Water Tunnels, the proposed mining/pumping of water from the Mojave Desert, Central Valley farmers lacking the water resources to maximize food production, and the Sacramento River and fishing stocks suffering from inadequate water flows. That connection is the State Water Project, which pumps water to Southern California and reduces the river water needed for fisheries, farmers, and the river itself. The reality is Southern California needs water and if we don’t produce it here, then we’re going to take it anywhere we can find it, regardless of environmental damage and economic considerations.
A Coastal Commission hearing on whether California American Water and others can appeal the Marina city denial of a key permit for the proposed desalination project is set for July 11 in San Luis Obispo. Cal Am, two members of the Coastal Commission and two local appellants are challenging the Marina city Planning Commission’s March 7 denial of a coastal development permit for the $329 million desal project, including seven slant source water wells and associated infrastructure proposed for the CEMEX sand mining plant, and segments of a source water pipeline to the desal plant and transmission main pipeline from the desal plant located inside both the city’s jurisdiction and the Coastal Zone under the Coastal Commission’s jurisdiction.
The California Department of Water Resources (DWR) announced they will provide a $10 million grant to public utility, California American Water. The grant money is destined to help build the seawater desalination component of the Peninsula Water Supply Project. “We are extremely grateful to DWR for supporting our project,” said California American Water president Rich Svindland. The Monterey Peninsula Water Supply Project is a $329 million project featuring a portfolio of water supply components to address the area’s water needs. Since 2005, DWR has completed three rounds of funding using Proposition 50 funds.
In early 2018, Cape Town, South Africa came dangerously close to being the world’s first major city to run out of water. People lined up for blocks to collect spring water. Stores sold out of receptacles like buckets and bowls. Bottled water was rationed in tourist-heavy parts of the city. April 12 was designated “Day Zero”—the day the water was expected to dry up. City officials prepared for riots, keeping army and police ready to be deployed to water collection sources.
These almost unlimited coastal access points are what made Kathy Biala move here five years ago. She’s taking me to one of her favorite walking spots on the shore, but before we reach the beach Biala wants to take me on a little detour. We drive past the wastewater treatment plant, then to the regional landfill, and finally to a sand mining plant — a post-apocalyptic looking moonscape where sand from Marina beaches gets packaged for places like Home Depot, golf courses, and concrete manufacturers. The state determined that it was causing some of the worst beach erosion in California.
San Diego regional water quality regulators today issued a permit for the installation of new, technologically advanced and environmentally sensitive seawater intake and discharge facilities at the Claude “Bud” Lewis Carlsbad Desalination Plant.
The plant – and the new permit – support Gov. Gavin Newsom’s April 29 executive order for California “to think differently and act boldly by developing a comprehensive strategy to build a climate-resilient water system.”
Under the new National Pollution Discharge Elimination System (NPDES) permit, the Carlsbad plant will continue producing about 50 million gallons a day of high-quality, drought-proof drinking water for the region as Poseidon Water and the San Diego County Water Authority develop a permanent, stand-alone seawater intake and associated structures.
Environmentally sensitive facility
The new intake-discharge system is needed for long-term operations of the nation’s largest seawater desalination plant, which started commercial production in December 2015 using water withdrawn from Agua Hedionda Lagoon for once-through cooling at the Encina Power Station. So far, it has produced more than 46 billion gallons of drinking water with reverse osmosis technology.
“The Carlsbad Desalination Plant is an invaluable asset for the state and region that helps us adapt to the changing climate and sustain a $231 billion regional economy,” said Jim Madaffer, chair of the Water Authority’s Board of Directors. “It is the most environmentally sensitive and technologically advanced plant of its kind in the nation – part of our commitment to collaborative projects and integrated water solutions for San Diego and the Southwest.”
Water supply sustainability
The closure of the power station in December 2018 led to temporary intake-discharge operations that will continue while new, stand-alone desal intake-discharge facilities are built. Conversion to stand-alone operations was anticipated in the 2012 Water Purchase Agreement between Poseidon, which owns and operates the desalination plant, and the Water Authority, which purchases the water for regional use. Currently, the plant provides about 10 percent of the region’s water supply.
“We are very thankful to the Regional Board for supporting the environmental enhancements of the Carlsbad project and water supply reliability for San Diego County,” said Poseidon CEO Carlos Riva. “This plant will continue to be a vital regional resource for decades to come and an example of how environmental stewardship can go hand-in-hand with water supply sustainability.”
Transition in three phases
With the permit in hand, the transition to the new intake and discharge facilities will be implemented in three phases:
- Temporary Operations – NRG, which owns Encina Power Station, continues to operate the water circulation pumps while an interim intake system is constructed.
- Interim Operations – Expected to begin in mid-2020, this phase uses new fish-friendly pumps as a replacement for the existing circulation pumps. A new, permanent screened intake system also will be designed and built in the lagoon during this phase of operation. The new intake will rely on innovative technology, including 1 mm screens that will further enhance marine life protection.
- Permanent Operations – The new submerged, screened-intake system is expected to be connected in late 2023, achieving the best available technology to minimize impacts to marine life in full compliance with the 2015 California Ocean Plan Amendment.
Once permanent operations begin, the Carlsbad Desalination Plant will be the first to comply with the 2015 Ocean Plan Amendment, designed to advance ocean water as a reliable supplement to traditional water supplies while protecting marine life and water quality.
Poseidon is also protecting the coastal environment by taking over responsibility for the preservation of Agua Hedionda Lagoon from NRG. As the lagoon’s steward, Poseidon Water is taking responsibility for ensuring the man-made lagoon continues to realize the life-sustaining benefits of an open connection to the Pacific Ocean through periodic maintenance dredging.
Dredging keeps sand from blocking the flow of ocean water in and out of the lagoon, maintaining its tidal circulation, which is needed to maintain a healthy marine ecosystem, support extensive recreational uses, sustainable aquaculture at Carlsbad Aquafarm, and a white seabass hatchery operated by Hubbs-SeaWorld. Dredging also helps replenish the sand on Carlsbad State Beach, which otherwise would revert to historical cobble-stone, with sand that is relocated from the lagoon to nearby shoreline.
Temporary operations are anticipated to cost about $6.5 million annually, increasing the cost of water from the plant in 2020 by about $135 per acre-foot. Permanent facilities are projected to cost between $66 million and $83 million. The Water Authority is seeking state grant funds to defray some of that cost.
The Water Authority purchases up to 56,000 acre-feet of water from the Carlsbad plant per year – enough to serve approximately 400,000 people annually. The plant is a major component of the Water Authority’s multi-decade strategy to diversify the county’s water supply portfolio and minimize vulnerability to drought or other water supply emergencies.