NATIONAL READY-MIX COVER STORY CARBON COUNTERBALANCE The National Ready Mixed Concrete Association Fleet Benchmark-ing and Costs Survey indicates one gallon of diesel per delivered yard, adding 40 kg CO 2 -eq/yd. to the Construction Process carbon tally. NRMCC is demonstrating how that number can become a minus 80 kg CO 2 /yd. by converting a sizable portion of its die-sel-powered mixer and dump/tanker tractor fleet to renewable natural gas. RNG turns the table on the carbon math stigmatizing cement and concrete in this era of greenhouse gas emissions (GHG) inventorying. Measured in diesel gallon equivalents (DGE), the fuel is derived from principal methane-emitting sources: Dairy farms, landfills and wastewater treatment plants. Like conventional nat-ural gas, RNG as a fleet fuel requires significant investment in compressor and station infrastructure—ideally installed within a planned or established truck parking area. NRMCC sources RNG from White Plains, N.Y. processor, supplier and fueling infrastructure contractor TruStar Energy. An initial con-tract covers RNG supply for the 120-unit fleet and four station ramp up. Next year, projected delivery will equate to 1.2 million DGE. Between TruStar and other processors/suppliers, present capacity for fuel-grade natural gas from waste methane sources across California amounts to 30 million DGE. Few, if any, peer operators have matched the transparency National Ready Mixed Concrete Co. exhibits with a breakdown of the impact that renewable natural gas has on enterprise carbon dioxide emis-sions reduction efforts. Material trucks and mixer trucks running RNG, processed from dairy farm methane reduces CO2 emissions in both the product stage and construction phase of any job. Like conventional natural gas, renewable natural gas as a fleet fuel requires significant investment in compressor and station infrastruc -ture—ideally installed within a planned or established truck parking area. Equipped for 50 mixers, NRMCC’s inaugural station was com -pleted in June 2020 at the Vernon Plant, whose 2017-19 construction plans anticipated a CNG/RNG-powered fleet for the downtown Los Angeles operation. A second station is under construction at NRMCC’s Irwindale Plant and scheduled to come on line by year end. Work is scheduled to com -mence in early 2022 on NRMCC’s Glendale and Santa Clarita plant CNG/RNG fueling infrastructure. Fueling station build contracts have been awarded to both Ozinga Energy (Vernon, Irwindale) and TruStar Energy (Glendale, Santa Clarita). www.concreteproducts.com November 2021 • 45
Concrete Products November 2021: Page 45
