Drought survival: O.C. makes 100 million gallons of wastewater a day drinkable
Like other water agencies in California, the Orange County Water District is looking at ways to encourage ratepayers to conserve. But it also is looking for sources of water to ensure that its customers don’t have to go without.
In May, the district entered negotiations with Poseidon Water to determine whether buying water from the company’s proposed ocean desalination plant in Huntington Beach would be worthwhile.
While those talks continue, the district reached a milestone that could be a big factor in how Orange County manages its water supply during the lingering drought.
The water district’s groundwater replenishment system, a purification facility tucked between the 405 Freeway and the Santa Ana River in Fountain Valley, recently underwent a $156.2-million expansion that bumped production from 70 million gallons of water per day to 100 million gallons per day. That’s enough for about 850,000 people.
The facility, the largest of its kind in the world, produces drinkable supplies from recycled wastewater to be stored in the county’s groundwater basin near Anaheim.
In a joint project with the Orange County Sanitation District, the water district purifies treated wastewater and injects the potable water into the underground basin to be used by 19 member agencies in its service area, which includes Huntington Beach, Fountain Valley, Costa Mesa, Irvine and Newport Beach.
“It’s the only thing that will get us through this [drought],” said Orange County Water District board President Cathy Green. “Our imported water has been cut back. This water could never be cut back. It’s ours.”
The partnership between the water and sanitation districts dates to the 1970s, when the water agency built Water Factory 21, one of the first facilities to use reverse osmosis to purify water, said Michael Markus, the Orange County Water District’s general manager.
Until it went offline in 2004, Water Factory 21 produced about 15 million gallons per day of potable water. But in the late 1990s, the water and sanitation districts were in the works to build a bigger facility capable of producing more water.
Jim Herberg, general manager of the sanitation district, said the wastewater agency was looking to build another outfall pipe to discharge its treated effluent. At the same time, the water district was looking for a new source of water for the county. Instead of disposing of the water in the ocean, the sanitation agency teamed with the water district to build the groundwater replenishment system.
In January 2008, the $481-million facility went online, providing up to 70 million gallons of potable water per day before the expansion.
The sanitation district currently treats about 190 million gallons of wastewater per day and disposes of about 90 million to 100 million gallons of treated effluent into the ocean each day. The remainder goes to the groundwater replenishment system to be purified as drinkable water and stored. Both agencies are awaiting a study to help determine whether it would be feasible to send more water into the groundwater system.
If the study is favorable, the water district says, it has enough room to expand its facility again to produce up to 130 million gallons per day of potable water.
“The sanitation district will be discharging next to nothing out to the ocean,” Markus said. “We’ll probably be recycling 85% to 90% of their flow.”
How groundwater replenishment works
Wastewater goes through three treatment components when it is purified by the groundwater replenishment system: microfiltration, reverse osmosis and ultraviolet light.
When treated wastewater from the sanitation district’s Fountain Valley facility arrives at the groundwater replenishment system through underground pipes, it undergoes a microfiltration process that removes any solids, organisms, bacteria and some viruses.
Like other major water purification systems, the major step in the process is the reverse osmosis treatment. Water is passed at high pressure through about 22,050 membranes to remove salt, viruses and pharmaceuticals.
Compared with ocean water desalination, the groundwater replenishment system’s reverse osmosis process uses less energy because less salt needs to be removed from the wastewater, Markus said.
Unlike desalination, the last step in the water district’s purification process is mixing the water with hydrogen peroxide and shining ultraviolet light on it to kill any remaining bacteria and viruses.
“The entire [purification] process only takes about 45 minutes,” Markus said.
Desalination or recycled wastewater?
Poseidon Vice President Scott Maloni said his company supports the groundwater replenishment system and recognizes it as the county’s top priority in supplying residents with water. However, desalination could contribute to that, he added.
“We think [the desalination plant] is complementary,” he said.
For nearly a decade, Poseidon has been trying to get its proposed $1-billion Huntington Beach desalination plant approved for construction. It has approvals from the city of Huntington Beach, the Santa Ana Regional Water Quality Control Board and the State Lands Commission but is waiting for a development permit from the California Coastal Commission, which may review the application late this year.
The facility, which is projected to produce 50 million gallons of potable water per day, would be next to the AES power plant at Pacific Coast Highway and Newland Street.
The project’s opponents claim that the cost of desalination would increase water rates and that the plant would consume a high amount of energy and harm marine life.
Maloni said permitting agencies have determined that the project “would not negatively affect marine life or degrade water quality,” and he believes the groundwater replenishment system is not drought-proof.
“During a drought, if there’s less water being consumed, then that means less water being recycled,” he said. “That affects the capacity of [the groundwater replenishment system].… Desalination is immune to those effects.”
Former Huntington Beach Mayor Debbie Cook, who for the past decade has been keeping a close eye on the Poseidon project, said ocean desalination should be the last route for the county and that expanding wastewater recycling should be a priority statewide.
“There are so many places along the coast that are dumping water that could easily be treated for a fraction of a cost of ocean desalination,” she said.
Water purified by the groundwater replenishment system is sold to the Orange County Water District’s member agencies for $294 per acre-foot, Markus said. In comparison, the district’s cost to buy imported water from the Municipal Water District of Orange County is about $660 per acre-foot for untreated water and about $1,003 per acre-foot for treated water.
The estimated cost of Poseidon’s water has yet to be determined. In May, the Orange County Water District approved a term sheet with the company that serves as the basis for negotiating the water’s cost. Currently, the agencies are using the price of treated Municipal Water District water as the base cost and tacking on premiums.
Poseidon previously stated that water from the Huntington Beach plant would cost about $1,812 per acre-foot. A 2014 study by consultant Clean Energy Capital estimated the median price at $1,922 per acre-foot.
Cook said it doesn’t make sense for the sanitation district to dump treated wastewater into the ocean to be pulled out later by a desalination plant.
“We dump effluent off the coast of Huntington Beach, and then Poseidon’s just going to suck the same effluent back into their pipes, but it’s going to be a lot saltier,” she said.
The drought and declining wastewater
In recent years, Herberg said, the sanitation district has treated less wastewater because residents are conserving water during the drought. The agency currently receives about 190 million gallons per day, but about a decade ago, it got as much as 220 million gallons per day.
“Our goal is to recycle as much as we get,” he said. “Wastewater flows are down, but we want to recycle 100% of it.”
In April, the State Water Resources Control Board set water-conservation benchmarks for cities and water agencies across California in an effort to reduce overall water use by 25%.
Markus said he has concerns about the decline in wastewater but believes the mandatory water restrictions won’t have a significant effect on the groundwater replenishment system.
“With the governor’s call for the 25% conservation, most of that is going to be outside the house,” Markus said. “But people will also be taking shorter showers and buying energy-efficient washers. I’m thinking maybe it’ll be about a 5% decrease in wastewater, but we’ll have to wait and see.”
Herberg said the groundwater system will remain crucial to Orange County’s water supply.
“It’s enormously important to Orange County and our region,” he said. “It has surpassed the flow of the Santa Ana River as being an important part of our supply. If we didn’t have the groundwater replenishment system, we would definitely be in a lot worse shape than we are.”