Recycled Water Plant Anchors Infrastructure Overhaul In SoCal

With its groundwater supplies dwindling, one California city is trying to increase its reliance on recycled water.

Paso Robles, a city of 30,000 in southern California, has upgraded its water and sewer plant and plans to finish a new recycled water plant in 2018. The city is located in San Luis Obispo County, a region enveloped in “exceptional drought,” according to the U.S. Drought Monitor.

Mayor Frank Mecham praised the city for readiness. “I think Paso Robles has really stepped up to the plate to provide supplemental water sources and take some pressure off the groundwater basin. Whatever anyone can do to relieve the basin from being pumped more should do it,” he said, per San Luis Obispo’s Tribune.

The overall price tag for the project is $77 million, according to The Tribune. The projects are “capable of producing as much as 7,300 acre-feet of water per year,” the report said.

The price on the sewage treatment plant was $47 million, the report said. And the recycled water plant clocks in at $18 million.

“With the completion of the sewer plant, the city is now ready to begin its third and final supplemental water project — a tertiary treatment plant that will clean the 2.7 million gallons a day of water produced by the sewer plant to the point that it can be used for irrigation at city parks and golf courses, and for other non-potable uses,” the report said, citing city planner Susan DeCarli.

“The Nacimiento water treatment plant cost $11.7 million and allows Paso Robles to use its allotment of 4,000 acre-feet per year from the Nacimiento pipeline. That means that during the winter months, the city of more than 30,000 can get most, if not all, of the water it needs from the pipeline and does not need to pump any groundwater,” the report said, citing Matt Thompson, the city’s wastewater resources manager.

“Demand for water decreases a lot in the winter because people don’t irrigate much, if at all,” Thompson said. “It really means that we can give the groundwater basin a rest.”

Groundwater problems in the area are not due to the drought alone. Pumping is also problem, leaving aquifer levels 70 feet below normal in some locations. “All three of the city’s water infrastructure projects will minimize the city’s use of groundwater and help stabilize the basin,” the report said.

For all things drought, visit Water Online’s Water Scarcity Solutions Center.