OCEANSIDE

Oceanside celebrated the start of construction Wednesday on a project that could make it the first city in San Diego County to be drinking recycled water by 2022.

At least two other cities or water districts are close behind on similar projects, and several more agencies are considering plans to make potable recycled water a significant portion of their supply.

The $67 million project will make the city less reliant on imported water and less vulnerable to natural disasters such as earthquakes and droughts. Also, recycling has the environmental benefit of using less energy than transporting fresh water hundreds of miles from Northern California and the Colorado River.

Groups such as The Sierra Club and The Surfrider Foundation support potable recycling because of the environmental benefits.

The Pure Water Oceanside system will use advanced technology to filter up to 5 million gallons a day and inject it through wells into the Mission Basin aquifer. The water will then flow through the aquifer more than a mile to the city’s production wells where, further filtered by several months underground, the water will be pumped out and treated more before it’s added to the local supply.

Potable recycled water is “the logical next step,” said Sandy Kerl, general manager of the County Water Authority.

Metropolitan Water District, the Los Angeles-based agency that supplies imported water to 19 million Southern California residents, also supports the Oceanside project.

Together, Metropolitan and the County Water Authority are expected to fund $25 million of the Oceanside project’s operating costs over the next 15 years. The city is pursuing grants and loans to further subsidize the project.

Oceanside has been pumping brackish water from the Mission Basin for more than 20 years and filtering it with reverse osmosis, the same process used to purify seawater at the Carlsbad desalination plant. The city now gets about 10 percent of its drinking water from the wells.

However, the water level in the aquifer is decreasing and becoming more brackish. Recharging the aquifer with recycled water will raise the level and reduce saltwater intrusion from the Pacific Ocean.