Norcal Waste Systems of San Francisco has announced that its subsidiaries serving the San Francisco—Sunset Scavenger, Golden Gate Disposal & Recycling, and S.F. Recycling & Disposal Inc.—now exclusively use alternative fuels in their trucks. The firms use liquefied natural gas in five collection trucks and eight transfer trucks.

In March, the rest of the firms’ 385-truck fleet switched to B-20, which features 20 percent biodiesel made from vegetable oil and 80 percent low-sulfur diesel. The switch will reportedly reduce annual greenhouse gas emissions by 5,400 tons.