“California first” for Cambi with three new thermal hydrolysis systems for biosolids digesters

The San Francisco Public Utilities (SFPUC) has selected three Cambi thermal hydrolysis technology systems for new biosolids digester facilities. The technology will allow the SFPUC to enhance odour control, boost energy recovery, and reduce the plant’s environmental footprint.

As part of a $3 billion upgrade, Cambi have been chosen to provide three of its acclaimed thermal hydrolysis systems (THP) for San Francisco Public Utilities Commission

The SFPUC is investing over US$3bn 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 programme.

The Biosolids Digester Facilities Project is an essential component of the larger Southeast Treatment Plant upgrade, which will replace and relocate the existing, outdated solids treatment facilities with more reliable, efficient, and modern technologies and facilities.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 new 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 centre, 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 said to be a “win-win” for Cambi and the SFPUC, as Cambi stated that this is “a major contract in the US” for them and the use of thermal hydrolysis technology could allow the SFPUC to produce higher quality “Class A” biosolids. The nutrient-rich wastewater by-product, known as biosolids, can be used as a high-quality fertiliser, expanding the by-product’s beneficial uses.

In addition, the Cambi technology allows the SFPUC to enhance odour 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,” said Eirik Fadnes, CEO of Cambi.

He added: “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.”

San Francisco marks Cambi’s first THP project on the West coast and tenth in the US

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 10th in the US, 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 investments to the Southeast Treatment Plant aims to reduce odours, with the goal of improving the quality of life for nearby residents and employees, earthquake resiliency, preparation for rise in sea levels, and ensuring operational redundancy and efficiency in the process. In addition, the upgraded facility aims to allow San Francisco to “look better, smell better, and work better for the community, SFPUC staff.”