The existing WWTP, located at 160 Atascadero Road in Morro Bay, was originally constructed in 1953 and upgraded in 1964, 1982, and 1984.
The existing WWTP was designed to treat an average dry weather flow of 2.06 MGD through a primary process (solids removal). The WWTP’s secondary (biological) treatment system can treat up to a nominal capacity of 1.0 MGD.
The existing WWTP is jointly owned and operated between the City of Morro Bay and Cayucos Sanitary District under a Joint Powers Agreement (JPA) and currently serves a combined population of approximately 14,000 people.
The existing WWTP is operated under National Pollution Discharge Permit (NPDES) No. CA007881, and the Waste Discharge Requirements were updated and adopted by the Regional Water Quality Control Board on December 7, 2017.
The existing WWTP has operated under a 301(h) modified discharge permit from full secondary treatment requirements since its last upgrade in 1984, to allow for partially treated wastewater to be discharged during wet weather periods when the plant cannot fully treat incoming wastewater flows. However, the updated Waste Discharge Requirements, which become effective on March 1, 2018, no longer include this waiver.
The City received a Time Schedule Order on June 27, 2018 from the Regional Water Quality Control Board which requires full permit compliance by February 28, 2023. If this deadline or other intermediate deadlines stipulated in the Compliance Schedule are not met, the City will face both mandatory and discretionary fines from the Regional Water Quality Control Board.
California Coastal Commission (CCC) denied a Coastal Development Permit (CDP) to upgrade the existing WWTP in 2013.
A letter issued by the Executive Officer of the Central Coast Regional Water Quality Control Board in February 2015, states that the agency expects a new facility to be fully operational by 2021.
The new Water Resources Center produces tertiary treated (filtered), disinfected effluent at minimum, and includes full advanced treatment capabilities to produce water for future injection to supplement the City’s groundwater supply.