An East County project to convert wastewater to drinking water is expected to be finished by 2026. Photo courtesy of the East County AWP Joint Powers Authority

An East County project to convert wastewater to drinking water is expected to be finished by 2026. Photo courtesy of the East County AWP Joint Powers Authority

Construction has started on a $950 million water purification plant in Santee that will provide enough drinking water to serve an estimated 500,000 people and businesses in East County.

The East County Advanced Water Purification Program will daily produce up to 11.5 million gallons of potable water which amounts to about 30% of the drinking water used by East County residents and businesses.


Scheduled for completion in the first quarter of 2026, the water purification project is being built and is owned and operated by the 
East County AWP Joint Powers Authority – a partnership among the Padre Dam Municipal Water District, the City of El Cajon, San Diego County and Helix Water District.

“The timing is great given the challenges of drought,” said Kyle Swanson, CEO and general manager of the Padre Dam Municipal Water District. “This is a new drought-proof supply in East County. It’s a great answer to today’s challenges.”


Hitting Needs


As an added environmental benefit, the project is expected to divert most of East County’s wastewater that would otherwise go to the Point Loma Wastewater Treatment Plant and discharged into the ocean, Swanson said.


The purification project also will ease pressure on the Colorado River, which Swanson said supplies about half of the region’s water.


“There’s just so much use and demand for that water on the Colorado River system that right now, we can’t keep up,” Swanson said. “The Colorado River is over allocated.”


Swanson said the water purification system is “just one of those projects that kind of hits all the needs.”


Filtering Wastewater


The heart of the project is an outdoor series of pipes and treatment basins.


Wastewater first goes through a series of filter that removes particulates down to a size 300 times smaller than a human hair, Swanson said.


From there, the water goes through a reverse osmosis process in which the water under high pressure is forced through membranes that remove everything down to a size that is 100,000 times smaller than a human hair, Swanson said.


In a third step, Swanson said that the water is disinfected with ultra violet light similar to what’s used to clean surgical instruments.


“You’re basically zapping anything else that made it through,” Swanson said.


The purified water will be pumped 11 miles through 24-inch steel pipes to the Lake Jennings reservoir in Lakeside.


Chlorine is added to the water before its pumped to Lake Jennings, then removed before flowing into the reservoir.


The purified water is blended with water already in Lake Jennings and treated again at the Helix Water District’s R.M. Levy Water Treatment Plant before being distributed as drinking water.


Cost Covered


About $800 million of the cost of the project has been secured through grants and low interest loans, Swanson said.


The expectation is that additional grants will cover the rest of the cost.


“It’s looking very positive on the grant funding,” Swanson said. “If we don’t get all or some of the grant funding, there is the possibility to go out to the bond market.”


Swanson said that the project will not result in higher rates for East County customers.


“It will be less expensive to actually design, construct and get it operating than the do nothing approach,” Swanson said. “Financially, it makes sense.”


The Program will be the first operating recycled water project in East County and the second in San Diego County after Pure Water Oceanside, which provides 20% of Oceanside’s water supply.


Pure Water San Diego is planned to be the third recycled water project in the county and is scheduled to provide more than 40% of San Diego’s water supply by 2035.


East County Advanced Water Purification Joint Powers Authority
Founded: 2019
CEO/General Manager: Kyle Swanson
Headquarters: Santee
Business: Water and wastewater recycling.
Employees: 5
Website: 
www.eastcountyawp.com
Contact: 619-258-4644
Notable:  The East County Advanced Water Purification Program is a regional water and wastewater project built in a partnership among Padre Dam Municipal Water District, the County of San Diego, the City of El Cajon and Helix Water District.