OHIOVILLE, Beaver County — On a hill, just yards from the Ohio state line, rose a Marcellus Shale natural gas drilling rig.

The rig and its operators were contracted by the Chesapeake Energy Corp., based in Oklahoma City, Okla., which has a presence in Pennsylvania's Marcellus Shale play.

Chesapeake's Jacque Bland, media specialist, and Jack Thompson, public affairs officer, conducted a tour of that drilling site in late June.

Chesapeake was founded in 1989 and is now one of the nation's largest natural gas producers with about 11,500 wells. Of these wells, about 160 produce natural gas based on horizontal drilling.

Dave Spigelmyer, Chesapeake's vice president-government relations, said the company is in compliance with all regulatory acts and state and federal agencies that oversee drilling and production, including the Clean Water Act; Underground Injection Control program of the Safe Drinking Water Act; Clean Air Act; Resource Conservation and Recovery Act; National Environmental Policy Act; and the Occupational Safety and Health Act.

These regulate various aspects of gas wells such as air quality, noise, surface water protection, water use, road use, public safety, waste disposal and wetlands.

To prepare a site for drilling, Bland said the company spends about four to six weeks to make the land level and to line the drilling pad with a spill proof material so any spilled oil, wastewater or drilling mud will not be absorbed into the ground.

Drilling sites operate 24 hours a day, seven days a week for three to four weeks. The crews that man the rigs spend two weeks living on site in portable trailers and then have two weeks off. The drilling sites are lighted at night, and usually there is some type of security on site.

Most of the crews are from western states, such as Texas or Oklahoma, but Spigelmyer said that should change as more Pennsylvanian residents are trained for this work.

The crane portion of the drilling rig is used to hold and guide pipe in place as it goes into the ground. The crane superstructure at the Ohioville site was three-stories tall.

Three 30-foot pieces of pipe are screwed together, and the 90-foot sections are continuously lowered into the hole behind the drill bit. Individual drill bits can cost up to $10,000 to $15,000.

This work is done by two men on the crane platform, physically hooking the ends of pipe sections together, while another man runs the crane from inside a computerized control booth. Crews work 12-hour shifts.

For horizontal drilling, Spigelmyer said, the pipes have an ever so slight bend with teeth or grooves on the sides to direct the pipe out from the drilling rig instead of down. Horizontal drilling technology allows more wells to be drilled with less disturbed surface area, he said.

“On a typical drilling space of 640 acres, instead of having 32 individual pad sites for 32 wells, horizontal drilling allows for six to eight wells per 3 to 5 acre pad,” Spigelmyer said.

The wells are typically drilled to 5,000 to 7,000 feet.

A blowout preventer is below the drilling structure. This is like the device that failed at the bottom of the Gulf of Mexico last summer on a BP oil rig that poured oil into the gulf.

However, the Ohioville blowout is on land, not a mile beneath the surface of water.

Drilling mud and water that comes to the surface as part of the drilling process is recycled as both an economic and environmental savings. After recycling began, drilling companies found that they had far less waste that needed to be hauled to landfills and disposed of, saving both money and the filling of garbage dumps, Thompson said.

After drilling is done, the fracking process begins with the removal of the drilling rig. Then water, chemicals and sand are pumped into the well under pressure. The pressure fractures the rock and the sand keeps the fissures open, allowing gases to escape the rock and come to the surface.

“We are reusing nearly 100 percent of water that returns to the surface during drilling and fracking processes,” Thompson said, adding that saves the amount of water needed to be trucked to the site. The fracking process uses up to 5 million gallons of water.

Once the well is producing, it is capped with a storage tank set up to collect any additional water or waste that comes up with the gas. All the structures are removed and the liners are taken up for disposal.

Then grass is planted to reclaim the site.

Once the reclamation process is completed, well sites are only occasionally visited by gas company personnel.

“The lights are gone, crews gone, rig gone, and it pretty much returns to what it was before we arrived,” Thompson said.