Effluent Recycling Pipeline
At the heart of the wastewater reuse system is a 50-mile pipeline that collects effluent from ten communities for injection in the Geysers geothermal steamfield. The first phase of the recycling pipeline was completed in 1997 between the Southeast Regional and Middletown treatment plants and the Geysers; the first segment of the Phase 2 pipeline was completed in 1999 with connection of the Clearlake Oaks treatment plant to the system; and the remainder of the Phase 2 pipeline to the Northwest Regional treatment plant was completed in 2003.
The system's first phase delivers an average of 5,400 gpm to geothermal injection wells operated by the Northern California Power Agency (NCPA) and Calpine Corporation. These industry partners have achieved a 70 MW increase in generating capacity since Phase 1 operations began. Phase 2 has increased effluent injection volume by approximately 20% in normal weather years, and by as much as 150% in drought years.