The U.S. Environmental Protection Agency has granted a waiver allowing the wastewater treatment plant serving Morro Bay and Cayucos to continue operating for five years as upgrades are completed.

The plant, which discharges into the ocean, has been operating under a variance that exempted it from fully treating wastewater. Although all of the wastewater receives a primary treatment, and gets disinfected, it did not necessarily all get secondary treatment. The plant treats on average 1 to 1.2 millions of gallons of sewage per day.

Central Coast Regional Water Quality Control Board spokesman Harvey Packard said the EPA’s decision was largely expected after the board voted last month to grant the plant a permit.

Morro Bay Mayor Janice Peters said upgrades are slightly ahead of schedule. She emphasized that most of the discharged water gets fully treated.

“Ninety percent or more of the time, we are running at full secondary treatment level anyway,” she said. “We have a really good record and we’re really proud of it.”

Several years ago, plant discharges were suspected of sickening sea otters, who were coming down with an illness transmitted by cat feces,  but the bacteria was later found to be coming into the ocean from freshwater streams.

The plant has also received praise for planning to implement tertiary treatment, the highest level of treatment, in its upgrade.

“The Cayucos wastewater treatment facility should be commended for moving full steam ahead toward tertiary treatment,” Alexis Strauss, water division director in the EPA’s Pacific Southwest region, said in a statement.