In 2011, Summit County's Sustainability Plan established a goal to reduce harmful greenhouse gases. Now part of that plan could include the expansion of vehicles fueled by compressed natural gas, or CNG.

According to Summit County Sustainability Coordinator Lisa Yoder, emissions produced from CNG vehicles are 30 to 40 percent lower than those produced by traditional gasoline engines. That fact in itself makes CNG vehicles an appealing investment for the county.

Summit County Public Works Director Kevin Callahan said part of the county's Sustainability Plan involved looking at the carbon footprint of all of the county's facilities and operations. Callahan said the review found that vehicle emissions represented roughly 25 percent of the county's carbon footprint, totaling "a couple of thousand tons of carbon per year."

Callahan said the county has several reasons to expand CNG in its vehicles, the primary being environmental and financial. With the latter, Callahan says the county spends around $900,000 per year on fuel. With the price of gasoline being "very volatile," he says switching to CNG is an efficient and reliable investment.

The county currently has around 250 vehicles in its fleet. After County Manager Bob Jasper decided to start a fleet committee that, to start, would analyze the feasibility of vehicles the county has for CNG as well as the turnover of vehicles within the fleet. Callahan said that report found that 15 to 20 vehicles per year are cycled out of the fleet.

"We started to look at converting vehicles from the standard fuel system to [compressed] natural gas and asked, 'What would the issues be?'" Callahan said.

One issue Callahan says the Summit County Sheriff's Office brought up was that CNG systems have been known to lose power with altitude. After working with Questar Gas, he says through the use of computerized systems CNG vehicles no longer have this problem. The gelling of CNG fuel in colder temperatures is also a problem Callahan says they want to solve.

Yoder also points out that because the storage tanks in CNG vehicles can be somewhat bulky, the amount of space in the bed of a pickup truck is reduced. Another hurdle involves the number of CNG refueling stations in the county. A release from the county last month stated that there is only one CNG station currently at the Top Stop on Park Ave. in Park City.

"You need a fueling facility that's relatively convenient to where the vehicles are housed in order to get people to change their preference," Callahan said.

In June, several public and private stakeholders met with the county to see how more CNG refueling stations could be brought to the county. Questar Gas has been helping the county get a refueling station in the Snyderville Basin, and Callahan says that there is interest in getting a station in Silver Creek.

Callahan says the fleet committee, in preparing for the 2014 budget, will be asking departments in the county to give them an analysis of what types of vehicles they will need. He says the committee will determine whether or not CNG vehicles are a good option for certain departments' needs.

"Right now we're on the soft path with CNG," Callahan said. "It's hard to get a full commitment until more fueling stations are in place. Because CNG is regulated by the state, there is a reasonable certainty that prices will remain consistently lower than gasoline."

The county and Park City are also exploring the potential of having a portion of their public transit fleet converted to CNG, and Callahan says the Utah Transit Authority is already doing so with a portion of their fleet.

There are a number of technical and logistical issues to go through first, Callahan says, but he thinks that in a decade the county could have a third to half of its fleet powered by CNG.

"Gasoline vehicles will become more efficient, but their reduction in emissions won't be anything close with what you would get with CNG," Callahan said.