East County AWP Program
AWP stands for advanced water purification — a treatment process to turn recycled water into drinking water. The East County AWP is a partnership between Helix Water District, Padre Dam Municipal Water District, the City of El Cajon and the County of San Diego to produce a sustainable water supply for east county.
Video Transcript: The Clear Solution
How It Will Work
Step 1: Recycled Water
Padre Dam Municipal Water District has been producing recycled water for irrigation and Santee Lakes for over 60 years. To provide recycled water for the East County AWP Program, Padre Dam will begin recycling wastewater from the City of El Cajon and the County of San Diego (Lakeside, Winter Gardens and Alpine).
Step 2: Advanced Treatment
The recycled water produced in step one will go through a four-step advanced treatment process — membrane filtration, reverse osmosis, advanced oxidation and disinfection — to produce water so pure that beneficial minerals must be added back into the water before it is finished.
Step 3: Detention
Padre Dam will transport the purified water through an 11-mile pipeline to Lake Jennings, where Helix Water District stores imported water from the Colorado River and Northern California, and local water from Lake Cuyamaca. State regulations currently require the detention of purified water in an aquifer or lake before it is distributed to homes and businesses.
Step 4: Treatment and Distribution
Helix treats the water in Lake Jennings at the district’s R.M. Levy Water Treatment Plant, and distributes the water to homes and businesses in the cities of La Mesa, Lemon Grove and El Cajon, the Spring Valley community and unincorporated areas of the county. The purified water from the East County AWP will provide up to 30 percent of Helix’s water supply.
When It Will Start
The East County AWP is scheduled to go online in 2025. There are three design and construction “packages” to fund and complete, and a fourth package focused on water treatment byproducts.
Design and construction of a new water recycling facility and the advanced water purification plant.
Design-Builder: Orion Construction
Design and construction of the pipeline to Lake Jennings, a dechlorination facility and an inlet, where the dechlorinated water will flow into the lake.
Design and construction of pump station expansions and improvements.
The East County AWP and the City of San Diego will determine how to dispose of brine and other byproducts of the advanced treatment process.
Take a Virtual Tour
This photo shows the East County AWP Demonstration Facility, which has been testing the advanced treatment process and effectively producing 100,000 gallons of purified water every day since 2015. Because of the pandemic, Padre Dam Municipal Water District is now offering virtual tours of the facility and the project.
Explore the East County AWP
Explore the program’s website, where you will find videos, a story map, fact sheets, studies and more.
Explore Orange County's AWP
Orange County’s Groundwater Replenishment System provides drinking water for 850,000 people.
Explore San Diego's AWP
The Pure Water San Diego Program will go online in 2035 and provide one third of the city’s water supply.