The approval will allow SoCalGas to start the design and the engineering phase.The present approval follows the last week’s approval of CPUC of the contracts signed by SoCalGas and the developers of the biomethane projects for building the infrastructure needed to connect each of the biomethane facility to the gas company’s pipeline system.

When complete, biogas from anaerobic digesters at 35 dairies will be collected and then cleaned to produce pipeline-quality renewable natural gas. The four new projects are part of the six pilot projects in the San Joaquin and Sacramento Valleys selected by the CPUC, the Air Resources Board (CARB) and the Department of Food and Agriculture, last December.

SoCalGasstrategy and engagement vice president Sharon Tomkins said: “In the last year we began injecting RNG into the SoCalGas system through a project at an anaerobic digester in Perris and a dairy digester pipeline cluster in Pixley.

“We look forward to bringing these four dairy biomethane projects online as we all work to help achieve California’s ambitious environmental goals.”

The new facilities are expected to be completed by next December and when combined, will produce enough RNG to fuel about 40,000 homes annually. Presently, there are about 37 dairy methane capture projects either operating or in the development and it is estimated that there could be nearly 120 projects funded and operating in the next five years.

California’s law requires that 40% of methane from the state’s dairies and other waste sectors to be captured, with provisions to deliver that energy to customers. The University of California estimates that the state’s existing organic waste could produce enough RNG to meet the needs of 2.3 million homes.

In February, the gas company and biogas producer Calgren Dairy Fuels announced that the RNG produced at Calgren’s dairy digester facility in Pixley, California is being injected into SoCalGas pipelines.