Wastewater Biogas Projects
Willdan Group Has Won a $31 Million Renewable Biogas Power Contract
Adam Harrie — July 16, 2026
Willdan Group was selected by Encina Wastewater Authority for a $31 million design-build contract to deliver a renewable biogas cogeneration project that converts biogas from wastewater treatment into on-site electricity. The system includes a new biogas conditioning unit, low-emission generators, emissions-reduction upgrades to existing equipment and a battery energy storage system paired with a microgrid controller.
Once complete, the project will enable Encina to use 100% of its renewable biogas resources to meet its current electricity needs, ensuring continuous service for more than 379,000 residents across North San Diego County, even during grid disruptions and blackouts.
Willdan Group has demonstrated how wastewater treatment facilities can convert an existing waste stream into a reliable, self-sufficient source of clean power while strengthening critical public infrastructure.
