Renewable natural gas (RNG) is set to take hold in Arizona and the high desert region of Southern California based on projects launched by Las Vegas-based Southwest Gas Corp.

The five projects would collectively supply 10 million therms of RNG from wastewater treatment and dairy sites. The first project is the Tres Rios Wastewater Project in Tucson, which is set to begin commercial operations in July.

The utility has been working with legislators and regulators “to pave the way,” and the projects “are just the beginning,” according to CEO John Hester.

Three projects in Arizona are at dairies. Paloma in Gila Bend would begin in October, with the Butterfield in Backeye in December and Milky Way in Maricopa targeted for startup in December 2022. The SoCal Biomethane...