Mitchell Cove: Home of the Outfall Pipeline

The hallmark rock tower (sea stack) at Mitchell Cove. It’s composed of the Purisima Formation; a Miocene aged sandstone.
The hallmark rock tower (sea stack) at Mitchell Cove. It’s composed of the Purisima Formation; a Miocene aged sandstone. The hallmark rock tower (sea stack) at Mitchell Cove. It’s composed of the Purisima Formation; a Miocene aged sandstone.

Welcome to what locals call the “stinky beach.” Located near the end of Almar Avenue, the smell varies depending on the day.

Coincidentally, the City of Santa Cruz Wastewater Treatment Facility’s outfall pipeline also begins here. However, the City’s Superintendent of Wastewater Collections and Treatment promises that the smell is TOTALLY independent of the pipeline and comes from natural decomposition of the kelp or seaweed.

The outfall pipeline is 12,250 feet long but because it makes a 90 degree bend after leaving the beach area, and then angles along the shore, it discharges the treated wastewater about one mile off shore where the water depth is 110 ft. It was completed in 1987 and given drought conditions currently handles 7.5 to 8 million gallons per day but was designed to handle in excess of 81 million gallons daily.

Wastewater includes all water generated indoors from sinks, toilets, showers, etc. The outfall handles any storm water that seeps into the system and approximately 1 million gallons per day from Neary Lagoon runoff. All water is treated at the plant to meet secondary standards before transport to the ocean. Storm water in many cases goes from storm water drains directly into the ocean (outflows at Auburn, Almar, and Woodrow are examples along West Cliff Drive).

The disposal pipeline leaves the beach from the rectangular cement structure on the right (west) side of the beach.
The outfall pipeline leaves the beach from the rectangular cement structure on the right (west) side of the beach.

The outfall pipe handles wastewater from within the City of Santa Cruz, Live Oak, Capitola, Soquel, parts of Aptos, and Scotts Valley (which treats it itself to at least a secondary level).  The City is not permitted to open the old 2000 foot disposal pipe, which runs next to the new 1987 pipe. This was done, however, during the El Niño year of 1991, for a few hours, to protect the infrastructure and prevent back flooding of wastewater.

Take the Self-Guided Mobile Tour

This piece is part of the West Cliff Drive Tour. Download the free app with many tours of the Santa Cruz area and beyond.

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Go to Mobile Ranger Guides in the Apple App Store
Go to Mobile Ranger Guides in the Google Play Store
  1. Sources Used

    • The Geology from Santa Cruz to Point Año Nuevo—The San Gregorio Fault Zone and Pleistocene marine terraces. By Gerald Webber and Alan Allwardt. In: Stoffer PW, Gordon LC, eds. Geology and natural history of the San Francisco Bay Area: a field-trip guidebook: 2001 Fall Field Conference, National Association of Geology Teachers, Far Western Section: September 14-16. USGS Bulletin 2188; 2001:194.
    • Living With the Changing California Coast. Gary B. Griggs, Kiki Patsch, Lauret E. Savoy. University of California Press; 2005.
    • Personal Communication with Dan Siedel, Superintendent of Wastewater Collections and Treatment Facility, Public Works, City of Santa Cruz, November 24, 2011 and August 14, 2014.
    • Personal Communication with Janice Bisgaard, Community Relations Specialist, Public Works, City of Santa Cruz, August 14, 2014.
    • Personal Communication with Steve Wolfman, Associate Civil Engineer, Public Works, City of Santa Cruz, 11/29 & 30/2011.
    • Waste Water Treatment Facility. The City of Santa Cruz. The City of Santa Cruz Website. www.cityofsantacruz.com/index.aspx?page=148.
    • Wastewater Treatment Facility. Santa Cruz LAFCO: Countywide Service Review. Public Review Draft. 2005. www.santacruzlafco.org/pages/reports/CSR Public Review Draft/03.Wastewater.PublicRevwDraft.06-05.pdf.



About The Author

I really enjoy field trips. I love being in a cool place and having someone tell me about it. The problem is, you can’t always find a professor or park ranger-type to tell you all they know about the local rocks, plants, and history. So I decided to combine my love of things natural with mobile technology.

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