BOULDER — Oil and gas companies drilling and operating future wells in unincorporated Boulder County may be assessed impact fees to mitigate the wear-and-tear their heavy trucks and other company vehicles are projected to cause on county roads.

The transportation impacts that oil and gas exploration and production might have on parts of eastern Boulder County’s roadway network — an area where drilling is most likely to begin, once a moratorium on accepting new drilling permit applications expires — could cost the county as much as $27.6 million in road repairs, reconstruction and associated safety improvements over a 16-year period, consultants told the Board of County Commissioners on Thursday afternoon.

Those impacts would include the deterioration that the heavy oil and gas trucks are expected to cause on unpaved and gravel county roads the companies may use to access the well sites, resulting in the need for grading, re-graveling, and more frequent application of dust suppressants, according to the consultants — representatives of BBC Research and Consulting and of Felsburg Holt and Ullevig, a transportation engineering firm — as well as George Gerstle, chairman of Boulder County’s Transportation Department.

Where paved county roads get the oil and gas companies’ heavy-truck traffic, there’ll be a need for more frequent and thicker asphalt overlays and road reconstruction. In some cases, such improvements as new or wider shoulders may be needed before drilling equipment even arrives, in order to make those now-narrow roads safer for the turning trucks as well as for the cyclists and motorists also traveling those roads.

Most of the road impacts, when the oil and gas companies’ heaviest trucks would be using those roads to get to and from well sites, will come during the actual drilling phase, said BBC Research’s Adam Orens.

The consultants said a loaded water truck, such as those that’ll be used during the drilling, has 5,500 to 11,000 times “the load impact” of a typical passenger car. A large semi truck carrying drilling equipment can have 20,000 to 30,000 times the load impact of a passenger car, they said.

Boulder County could offset its projected costs by charging oil and gas companies a “road deterioration and safety fee,” county officials and their consultants told Commissioners Cindy Domenico, Will Toor and Deb Gardner.

The consultants have suggested a fee of $1,200 for each well pad and another $36,900 for each well actually drilled — with some pads serving multiple wells. That’s based on current dollar values, and the fee could be raised, if need be, to cover inflation and any escalation in the costs of materials used to repair the roads traveled by the trucks and other vehicles.

County commissioners took no formal action Thursday on the fee-imposition proposal. But they gave the Transportation and Land Use departments’ staff and the county attorney’s office a go-ahead to draft regulations that — if adopted — would add the new oil and gas development transportation impact fee to Boulder County’s Land Use Code. Public hearings and formal Planning Commission and Board of County Commissioners’ action on the proposed fees may be scheduled in January, Gerstle said after Thursday’s meeting.

Thursday’s commissioners’ session was markedly quieter — and attracted a much smaller crowd — than a Tuesday board meeting on other proposed Boulder County oil and gas regulations that drew an overflow standing-room only crowd. A number of people attending Tuesday’s meeting disrupted and delayed the start of a public hearing by chanting demands that the county prohibit “fracking,” the hydraulic fracturing system that injects a mixture of water, sand and chemicals to free up underground deposits of oil and gas.

About 20 people showed up for Thursday’s road-fees discussion, and all but a handful of them were members of the county staff or representatives of the consulting firms. Thursday’s audience included two uniformed Boulder police officers. While Thursday’s meeting didn’t include a public hearing, the police presence reflected the additional security the commissioners announced on Wednesday that they’d have in place at future hearings on oil and gas issues, “to ensure that everyone is made to feel welcome for taking the time to allow his or her voice to be heard.”

John Fryar can be reached at 303-684-5211 or jfryar@times-call.com.