As diesel fuel prices continue to remain low, waste haulers plan on staying committed to natural gas-powered vehicles for their fleets.

In July, Phoenix-based Republic Services announced the addition of 17 compressed natural gas (CNG) solid waste collection trucks to its fleet in the Denver area. This brings Republic’s total number of natural gas-powered vehicles in Colorado to 82.

“We are proceeding with our CNG strategy while monitoring fuel prices,” says Steven Saltzgiver, vice president of fleet management for Republic Services.

Since the beginning of this year, the percentage of CNG trucks, relative to Republic’s overall fleet, has increased from approximately 14 percent to 15 percent.

“We have delivered more than 130 CNG trucks so far this year, and anticipate delivering more than 150 additional CNG trucks by the end of year,” says Saltzgiver.

Republic operates a fleet of more than 2,200 CNG vehicles and 38 natural gas fueling stations, nationwide.

Harland Chadbourne, director of purchasing for Waste Pro USA, says the Longwood, Fla.-based company also remains committed to growing its CNG fleet and fueling facilities because of its benefits.

“CNG continues to be a safe and reliable fuel source that burns cleaner than diesel and gasoline fuels,” he says. “Using CNG also moves Waste Pro away from our dependency on petroleum-based fuels and reduces the supply and demand volatility that comes with imported fuels. Additionally, our customers prefer our use of the fuel as many of them have complimented on how quiet our trucks operate when compared to the diesel models.”

Since the beginning of the year, Waste Pro USA has committed to build one new fuel station as well as expanding and upgrading two other facilities. About 10 percent of its fleet, 190 trucks, are CNG-powered.

While Ray Burke, vice president of business development, solid waste at Clean Energy Fuels Corp., admits that lower diesel prices have made the push for CNG a little more difficult, the first half of 2015 has been one of the busiest for the company’s solid waste business.

“Clean Energy completed 14 new station projects for waste customers during the first six months and we project to complete at least 22 additional projects before the end of the year,” he says. “The waste industry was one of the first to test and then fully adopt natural gas as a fuel. It knows there are additional benefits besides the lower costs. The price of natural gas has been stable—and low—for many years, it burns cleaner, which helps waste companies win municipalities’ business, and the trucks are quieter. The pace of adoption of natural gas in the waste industry continues to be very strong.”

The Newport Beach, Calif.-based company has not seen any fall off of CNG adoption since the first of the year.

“Those that began to adopt natural gas years ago continue to add to their fleets, while more and more municipalities and companies make the switch for the first time,” says Burke. “Even with low oil prices, the diesel commodity is still a 70-percent priced commodity. Another important point is that the price of natural gas has been consistently low for the last five to six years since so much of it was discovered in the U.S. and most energy experts believe this will be case for the foreseeable future. We still import a lot of oil, which remains a volatile-priced commodity. It might be lower today, but these same experts believe it will rise in the next one to two years.”