Morro Bay and Cayucos Sewage Treatment Plant Upgraded

Last Updated: March 2008

    Nearly 30 years ago the federal Clean Water Act required cities- of all sizes- to upgrade their sanitary sewage systems and stop dumping untreated sewage into our ocean and open waters.  The Clean Water Act required full secondary treatment.  For nearly 30 years, the coastal towns of Morro Bay and Cayucos (together operating a single sewage plant) have been asking for and receiving waivers from the act. 

     For 25 years the Central Coast communities of Morro Bay and Cayucos have shared a sub-standard sewage treatment plant. Although the Clean Water Act (CWA) calls for a minimum of secondary treatment, the Morro Bay/Cayucos Plant doesn’t have the capacity to treat the sewage of a summer weekend; primary ‘treated’ sewage is mixed with what secondary treated sewage the plant can produce. The blend is then chlorinated and pumped about a mile offshore into shallow Estero Bay. Except for San Diego, Morro Bay/Cayucos is the last coastal community to be granted waivers from the CWA

   All this time, Estero Bay has been a ‘hot spot’ for sea otter death. In Estero Bay sea otter carcasses are found at four to five times the rangewide average. In 2004, 2005, and 2006; 43% 50% and 33% of the local area spring count was found dead. Beach stranding rates in Estero Bay are double similar areas in Monterey Bay. Although it is technically correct that no absolute link has been made between sewage and sea otter death, The Otter Project believes otters will thrive in clean seas.

   The Otter Project, together with NRDC and the Santa Lucia Chapter of the Sierra Club, aggressively opposed the granting of a new waiver in 2006. Members of The Otter Project came through again, sending letters to the Morro Bay and Cayucos city councils. We appeared at city council meetings, in the community, before the Regional Water Quality Control Board, and even before the Governor’s Ocean Protection Council.

    In the summer of 2007, Morro Bay and Cayucos embraced change for the good and voted to upgrade their sewage treatment plant to a modern, tertiary standard. The communities are even considering a technically advanced level of treatment that will allow them to reuse the water within the community.  The Otter Project and our partners have followed up by supporting Morro Bay and Cayucos efforts to obtain state grants available to small communities.

    The bad news is that they want several more years to do the upgrades. Why is this bad news? Because this means that the San Luis Obispo County area has to endure several more years of bacteria and pollutants spewing into Estero Bay, threatening all who swim in those waters - from humans to sea otters. Pollutants from the sewage treatment plant degrade marine ecosystems and threaten human health. 

   Although the construction time for the Morro Bay sewage plant upgrade to meet basic federal standards is less than two and a half years, plant officials do not intend to complete the project until March 2014. The plant's own documents show that a faster, more efficient upgrade is not only possible, but would be less expensive as well. Morro Bay and Cayucos can upgrade their facilities on a much shorter timeline. Other central coast sewage treatment plants managed to do their upgrades in an average of five years. There is still a small chance for a backslide and The Otter Project, NRDC, and Sierra Club will continue to be involved until a tertiary plant is realized seven years from now. 

Facts about the Morro Bay-Cayucos Sewage Treatment Plant

• The Morro Bay-Cayucos Sewage Treatment Plant is one of the only treatment plants in California operating with a waiver from federal sewage treatment standards. This means the plant is allowed to discharge primary-treated sewage into the ocean. During primary treatment, wastewater is screened for the removal of solids, grit, and primary sedimentation, then is chlorinated for disinfection.
• The plant treats only part of its wastewater to secondary treatment standards, which utilize special strains of aerobic bacteria (bacteria that need oxygen to grow) to break down the organic waste left after primary treatment. Secondary treatment removes up to 95 percent of suspended solids in the waste stream and is significantly more effective than primary treatment in removing biologic pathogens from sewage. For example, secondary treatment removes 80 to 90 percent of shigella bacterium, 70 to 99 percent of salmonella, and 75 to 99 percent of enteric viruses prior to discharge of the effluent.
• The plant discharges its wastewater just a half-mile offshore, just northwest of Morro Rock, at a depth of 50 feet. The World Health Organization recommends sewage outfalls to be a minimum of one mile offshore and/or at a minimum depth of 60 feet.
• The most recent major upgrades to the plant occurred more than 20 years ago in 1983 and 1985.
• For more information about the plant, you can visit the Morro Bay Public Services Department website.

Morro Bay Coastal Waters: "Hotspot" for California Sea Otter Infection

• Morro Bay has one of the highest rates of otter infection from the parasite Toxoplasma gondii (T. gondii). T. gondii can cause encephalitis, which affects the brains of infected animals, causing a variety of physical symptoms such as muscle tremors, recurrent seizures and decreased or abnormal motor function. Encephalitis is a major contributing factor in the death of sea otters from both shark attack and cardiac disease.
• California sea otters living in the Morro Bay area are nine times more likely to be infected with T. gondii than sea otters elsewhere in their range.
• The area from Cayucos to Hazard Canyon along the Central Coast had the highest number of otter strandings in the otters' region, 77 in 2004.
• Morro Bay is the only region in the California sea otters' range where primary-treated effluent is discharged into the nearshore marine environment.
• A prominent biologist with the California Department of Fish and Game names "the discharge of primary treated sewage" as a leading factor that may account for the Morro Bay T. gondii hotspot.
• For more information about the sea otter and research regarding potential causes of otter mortality, you can visit the Sea Otter Alliance website.

Facts About Upgrading the Sewage Plant

• The Morro Bay-Cayucos Sewage Treatment Plant has indicated its intent to upgrade to full secondary treatment capacity, but construction is not scheduled to begin until the year 2012. The project is not slated to be finished until at least 2014.
• In contrast, the average upgrade time for sewage treatment plants in the Central Coast region is only five years -- all for plants larger than Morro Bay-Cayucos.
• An environmental expert estimated that the Morro Bay-Cayucos Sewage Treatment Plant could in fact be upgraded in as little as four and a half years.

 For More Information:

Comments from the EPA and Department of Interior regarding adverse effects on the environment from the Morro Bay-Cayucos Sewage Treatment Plant, January 8, 2008 (pdf)

Letter sent by The Otter Project to the EPA and the Fish and Wildlife Service Officials regarding Morro Bay-Cayucos Sewage Treatment Plant, December 17, 2007 (pdf)

Letter sent by The Otter Project to EPA Biologists regarding EPA Biological Evaluation for Morro Bay-Cayucos Sewage Treatment Plant, September 18, 2007 (pdf)