Historically, a portion of the city’s water supply – which is delivered to 45,000 metered accounts – has come from the Mission Basin Aquifer. However, water stored within the aquifer is decreasing from long-term use and drought.
Scientists and engineers have worked in partnership with Oceanside city planners to identify a potential new drinking water source utilizing the groundwater basin.
The solution: the Pure Water Oceanside facility, which uses advanced technology to replicate nature’s water purification process to create a new source of drinking water. It is the first water reuse project to go online in San Diego County.
The $70 million project uses reclaimed water from the San Luis Rey Water Reclamation Facility, which treats the majority of Oceanside’s water to recycled water standards and supplies the Pure Water Oceanside facility through advanced technology – ultrafiltration, reverse osmosis (RO), and advanced oxidation – to replicate and accelerate the natural recycling process.
Starting this year, the project will provide more than 20% – or three to five million gallons per day – of Oceanside’s water supply in keeping with capacity designs.
Filtration with filters 300 times smaller than a human hair remove small particles from the reclaimed water. RO uses ultrafine filters 100,000 times smaller than a human hair to remove salts, chemicals, bacteria, viruses, microplastics and pharmaceuticals.
In the final polishing step, advanced oxidation uses UV light and chlorine to neutralize any remaining trace substances. It is the same technology used to sterilize surgical equipment and baby food jars.
The water at this point is so pure it is near distilled in quality and meets or exceeds drinking water standards. Minerals are added to the water and then injected into the Mission Basin Aquifer.
The water remains underground for several months – providing additional treatment – and then is extracted from the aquifer and treated again at the city’s Mission Basin Groundwater Purification Facility.
The project is designed to provide new local high-quality drinking water that is clean, safe, drought-proof, environmentally sound and cost effective. Pure Water Oceanside will recharge the local groundwater basin, minimize seawater intrusion, and improve the basin’s water quality.
Recently dedicated in a public ceremony, guests took guided tours of the Pure Water Oceanside and San Luis Rey Water Reclamation facilities. It also is receiving overwhelmingly positive approval by local residents, according to Lindsay Leahy, P.E., City of Oceanside principal water engineer.
The foundation of the project was a goal set by the Oceanside City Council directing the city’s Water Utilities Department to develop a 50% local supply by 2030 to move toward water independence, notes Leahy.
The city then studied potable water reuse and desalination feasibility.
