When California's South Coast Air Quality Management District enacted part of Rule 1110.2 in 2008 covering operation of engines fueled by natural gas or biogas, Inland Empire Utilities Agency faced a challenge.
The agency had been using biogas from its wastewater treatment plant in Ontario, Calif., to run two 1.4 MW engine-generators, providing 30 percent of the plant's electrical needs. The new regulation forced the shutdown of one engine to meet emissions requirements.
IEUA had an energy independence plan to go gridless by 2020, relying heavily on renewable energy. To meet the new air-quality
