SFPUC selects Cambia technology for new biosolids digesters

By Cambi | November 14, 2022

The San Francisco Public Utilities Commission and Cambi, the world leader in thermal hydrolysis for wastewater treatment, are pleased to announce an agreement for the installation of three thermal hydrolysis systems as part of the Biosolids Digester Facilities Project at the Southeast Treatment Plant in San Francisco. The contract will be signed in the coming days.

The SFPUC is investing over $3 billion to upgrade and modernize the Southeast Treatment Plant, the City’s largest wastewater treatment facility, as part of a more extensive citywide Sewer System Improvement Program.

The Biosolids Digester Facilities Project is an essential component of the larger Southeast Treatment Plant upgrade and will replace and relocate the existing, outdated solids treatment facilities with more reliable, efficient, and modern technologies and facilities. The new digesters will use a state-of-the-art sludge treatment line using Cambi’s thermal hydrolysis systems.

“We are making generational investments at the Southeast Treatment Plant, our largest wastewater treatment facility,” said Dennis Herrera, General Manager of the SFPUC. “We took great care in designing it to be a modern and efficient resource-recovery center, improving operations and the well-being of employees and nearby residents. We are pleased to see the project taking another major step toward completion with this contract for thermal hydrolysis technology. This is about doing what’s right for our communities, the environment, and our ratepayers.”

The contract is a win-win for both Cambi and the SFPUC. It is a major contract in the United States for Cambi, a Norway-based company, and the use of thermal hydrolysis technology will allow the SFPUC to produce higher quality “Class A” biosolids. The nutrient-rich wastewater byproduct, known as ‘biosolids’, are used as a high-quality fertilizer. The higher classification will expand the byproduct’s beneficial uses.

In addition, the Cambi technology allows the SFPUC to enhance odor control and boost biogas output and energy recovery. Once operational, the new facilities will reduce the carbon and environmental footprint associated with biosolids management.

“We are honored to have a role in assisting the SFPUC in achieving their ambitious sustainability goals. Thermal hydrolysis was selected as a core technology for the project in 2016 to provide greater security as biosolids regulations become increasingly stringent and restrictive. We look forward to getting started on this important delivery for the metropolitan area of San Francisco,” said Eirik Fadnes, Cambi CEO.

The project is carried out by a joint venture of MWH Constructors and Webcor Builders. Cambi has worked with MWH on several thermal hydrolysis projects in the US and other countries.

The project is Cambi’s tenth in the U.S. but the first on the West Coast. The current project timeline plans the delivery of the thermal hydrolysis systems in 2027 and commissioning in 2028.

The large-scale investments to the Southeast Treatment Plant will reduce odors – improving the quality of life for nearby residents and employees. It will also improve earthquake resiliency, prepare for sea level rise, and ensure operational redundancy and efficiency. Once the upgrades are finished, the upgraded facility will look better, smell better, and work better for the community, SFPUC staff and all of San Francisco.

The Sewer System Improvement Program

Every day, 1 one million residents, businesses, and visitors rely on our combined sewer system to protect public health and the environment. The investments at the Southeast Treatment Plant are part of the Sewer System Improvement Program (SSIP), a multi-billion-dollar investment to upgrade and modernize San Francisco’s critical sewer infrastructure with new technologies to improve operations, reduce odors, better manage stormwater, and safeguard against climate impacts, like sea level rise. Projects across the City range from neighborhood green infrastructure like rain gardens that collect and clean stormwater, to extensive treatment plant upgrades. sfpuc.org/ssip