News Feature | September 13, 2017

California Wastewater Plant Overcomes Salt Crisis

Sara Jerome

By Sara Jerome

san elijo reg new

Treatment processes at a wastewater plant in California hit a snag recently when the facility was inundated with salt.

Rain and runoff increased the amount of salt at San Elijo Joint Powers Authority (JPA) wastewater treatment plant, according to the San Diego Reader.

“The salty water killed the beneficial bugs, and the water being treated wasn’t fully cleaned, leaving the plant with three days of too many suspended solids in the wastewater pumped into the ocean,” the report said.

An issue like this one can mean regulatory problems for a utility. The plant reported numbers as high as 10 times above the permissible amount of suspected solids for a week, according to the San Diego Regional Water Quality Control Board.

Michael Thornton, general manager for the JPA, explained how the facility responded.

“If you get a toxin in your plant, it takes three to six days to get it out of the system,” he said, per the report. “We weren’t sure precisely where the saltiness came from, but we have a lot of pipes in the coastal low lying areas and the water actually leaches into the pipes.”

Another facility managed to come to JPA’s rescue.

“We called other wastewater treatment plants and said we need some seed sludge,” he explained. “We sent a tanker to pick up 35,000 gallons of sludge, brought it back and added it, and monitored it to be sure the seeding worked.”

Initially, this solution did not work. But within days, JPA was back in compliance.

“The first three tries (105,000 gallons of borrowed sludge) did not take — there was still too much salt in the fermentation pools and the guest bugs died. But the fourth load of sludge worked — the microorganisms survived and thrived,” the report said.

JPA outlines the wastewater treatment process it uses here.

Image credit: "San Elijo Lagoon," Tim Buss © 2013, used under an Attribution 2.0 Generic license: