Ever drive by the EQT gas station in the Strip District and wonder about the bulky, unfamiliar pumps?

Puzzle no more. The alien pumps at the EQT station, as well as at three others in and around Pittsburgh, fill specially outfitted vehicles with compressed natural gas (CNG).

Although CNG vehicles have been around for decades, the American fleet makes up only 112,000 of the world’s 14.8 million. But in Pennsylvania, federal and state incentives and plentiful natural gas from local shale drilling may soon bring more CNG pumps to a gas station near you.

In total, five new CNG stations are planned for Pittsburgh’s corner of Pennsylvania. To Richard Price, executive director of alternative-fuel advocacy group Pittsburgh Regional Clean Cities, these developments augur a natural-gas-vehicle renaissance in the Steel City. He says, “I think we’re right on the cusp of it.”

Two of the CNG stations are scheduled in Sewickley and Harmar Township. The Harmar location, slated to open this fall, will service a new, nearby terminal for Pitt Ohio, a Pittsburgh-based trucking company. Other companies with established natural gas pumps for their fleets include Giant Eagle, U.S. Steel and Iron City Uniform.

Denny Martin, Pitt Ohio’s director of maintenance, says CNG technology is improving. “It’s all to be determined over time, but the equipment is getting better and better each year,” says Martin. To save on fuel costs and mitigate the environmental impact of its fleet, Pitt Ohio will build six CNG tractors for the Harmar terminal.

Natural gas burns cleaner than conventional fuels and currently costs about 40 percent less than diesel or gasoline. But new CNG vehicles and conversion services are pricey, and the gaseous fuel yields less bang per gallon than liquid fuels. That’s why medium-range CNG vehicles in commercial or government fleets, some serviced by privately owned refueling centers, give the greatest return on investment.