Morro Bay residents are facing minimum monthly sewer bills of around $35 to pay for an upgraded sewage plant with secondary treatment, the City Council heard at its May 14 meeting.
Officials in Morro Bay and Cayucos are considering whether to upgrade their jointly operated sewage plant to tertiary treatment a final stage of filtration in response to calls from residents and environmental groups who want the ocean outfall off Morro Strand beach cleaned up to the highest possible level. The issue is due for discussion at a May 24 meeting of the two boards.
Providing secondary treatment for sewage from the two towns would cost $24 million, with higher costs for tertiary treatment, according to consultants Carollo Engineers. The projected 78 percent increase in monthly sewer bills for Morro Bay residents assumes a worst-case scenario, with no grant funding available and ratepayers funding the entire cost of the upgraded plant, the report says.
The City Council is also considering a new treatment facility for a portion of city sewage in the Chorro Valley, where tertiary-treated effluent would be discharged to flow into Chorro Creek rather than the ocean. This option may be eligible for grant funding because it would enhance wildlife habitat in the creek and estuary, and could also augment groundwater for city wells, the report states.
Using a reverse-osmosis membrane system at the Chorro Valley plant would provide "the best technology available for water treatment today," the council was told, but it would be expensive to operate. Contaminants filtered out by the membrane would be discharged through the existing outfall pipe under this plan.
Tertiary treatment could also be provided at the existing sewage plant on Atascadero Road to create reclaimed water.
A comprehensive comparison of treatment alternatives, including "project costs and the pros and cons," will be presented to the Morro Bay City Council on May 28.