Riverside Moves Closer to Turning Sewage Waste into Renewable Natural Gas

The City Council on Tuesday approved a step that will transfer existing utility agreements at the city's water treatment plant to a bioenergy company to support a project that would convert organic waste into renewable natural gas.

City staff said the move is meant to turn sewage plant waste from the water treatment plant into a new local energy source that can be used instead of fossil gas.

The city also said the project supports its efforts to comply with state food-waste diversion rules and make better use of material that would otherwise be discarded.

The water treatment plant has been a key piece of Riverside's long-term sustainability plans since a $192 million expansion and rehabilitation project was completed in 2017.

The city has worked on the project for several years. In 2020, it approved an engineering study with Southern California Gas Co. That work was later expanded through additional change orders, including one in 2025 that increased the planned volume of renewable natural gas the system could handle.

The council's move on Tuesday transferred its agreements for the project with SoCalGas to Riverside Bioenergy Facility LLC — giving the private partner control of the rights and responsibilities tied to the gas interconnection needed to move the project forward.

The council also approved a public-private partnership with Riverside Bioenergy Facility in 2023 and later amended the lease agreement in 2025, shifting the cost of building the biogas upgrading facility and related piping to the private company.