East County AWP Program
AWP stands for advanced water purification. It’s a treatment process to turn recycled water into drinking water. The East County AWP is a partnership between several groups – Helix Water District, Padre Dam Municipal Water District, the City of El Cajon and the County of San Diego are producing 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. These steps are membrane filtration, reverse osmosis, advanced oxidation and disinfection. They will produce water so pure that we must add helpful minerals back into the water before we distribute it.
Step 3: Detention
Padre Dam will transport the purified water through an 11-mile pipeline to Lake Jennings. There the water will be stored with water from the Colorado River and Lake Cuyamaca. According to regulations, the water must be stored in a lake or aquifer before it is distributed to customers.
Step 4: Treatment and Distribution
Helix treats the water in Lake Jennings at the district’s R.M. Levy Water Treatment Plant. It’s then distributed 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 participating agencies held a groundbreaking ceremony on June 1, 2022 to launch construction. There are three design and construction “packages” to fund and complete. A fourth package focuses on water treatment byproducts.
East County AWP is expected to go online in 2026.
Design and construction of a new water recycling facility, advanced water purification facility, solids handling facility, product water pump station and a new visitor’s center.
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.
The East County Advanced Water Purification program offers multiple tour options. These include a 360-degree virtual reality video and online, staff-led tours.
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.