Full-Scale Sidestream Wastewater Treatment System

Oro Loma Sanitary District Wastewater Treatment Plant

Full-Scale Sidestream Wastewater Treatment System

First Wastewater Treatment of its Kind in the Western U.S.

The San Francisco Bay receives some of the highest unit nitrogen loading of any estuary in the United States. Estimated capital costs to upgrade San Francisco Bay Area wastewater treatment facilities to treat nitrogen are estimated at upwards of $12 billion. Oro Loma Sanitary District (20 million gallons per day permitted capacity; medium-sized plant), formed in 1911, is one of the first agencies in Alameda County, California. As a special district, Oro Loma provides wastewater collection and treatment, solid waste and recycling services. 

The project, funded by a U.S. Environmental Protection Agency regional grant and Oro Loma Sanitary District/Castro Valley Sanitary District, represents a significant collaboration between Microvi, OLSD, HDR and EKI Environment & Water. This full-scale unit utilizes Microvi’s MicroNiche Engineering™ technology to treat the facilities' biosolids handling return streams, also known as the sidestream. The sidestream represents on average approximately 20% of the plants' discharge nitrogen load which translates to about 400,000 pounds per year at OLSD. The system will reduce the nutrient load by 8 million pounds over 20 years. To build on this water quality legacy, the project also established a local internship program to provide training and career pathways into the wastewater industry.

Our role is focused on technology validation from startup in April 2021 through 2023. Validation testing will include data trending analysis to confirm performance reliability and various bench-scale testing efforts that will focus on technology design criteria, plant-wide benefits, etc. 

Since startup, the system has been able to achieve greater than 90% ammonia load reduction and it appears to have additional treatment capacity beyond the design conditions. The results occur with a retention time of approximately 24 hours with little to no biosolids production, which is unprecedented, compared to available competing technologies. 

A grand opening of the MNE treatment system was officially celebrated on December 8, 2021. The event provided an exclusive first look at the technologically advanced MNE treatment system housed in OLSD's retrofitted 90,000-gallon basin.

Oro Loma Sanitary District Wastewater Treatment Plant
Oro Loma Sanitary District and Castro Valley Sanitary District

Alameda County, CA
United States

12 MGD Facility