Putting out the welcome mats
by Evelyn SchlatterSouthwestern Wyoming’s Upper Green River Valley is home to the most extensive wetlands and riparian areas in the state, and its vast sagebrush prairies have long been a stronghold for sage grouse, antelope and mule deer. The Upper Green is also the site of the huge Jonah natural gas field.
The Jonah Field stretches over 32,000 acres and yields 255 billion cubic feet of natural gas each year. The impact of all that production on the land, air and wildlife has been severe. But one company, EnCana Oil and Gas, Inc., is trying something a little different to help minimize its harm.
About 18 months ago, the Bureau of Land Management allowed EnCana to start using wooden mats to protect the landscape around its Jonah gas wells. “Imagine a hardwood floor placed on top of an acre of prairie,” says Randy Teeuwen, EnCana community relations adviser. Measuring about 10 feet by 10 feet and weighing around 2,000 pounds, the mats protect topsoil from drilling equipment and the treads of heavy trucks, leaving the root systems of plants and grasses intact so they can recover faster.
EnCana lays the interlocking mats -- typically about 3,000 of them – directly over vegetation on flat drilling sites instead of clearing bare earth pads for wells. The mats provide a path from roads to gas wells, so that vehicles need not come into direct contact with the soil. The company leaves the mats in place for about 30 to 45 days, or until it completes drilling, and then moves them to another drill site. A plastic liner below the mats traps condensation and seems to provide moisture to the vegetation underneath it, Teeuwen says, helping the plants recover once the mats are removed.
“Once we remove the mats, we pretty much leave the area alone,” Teeuwen says. Even when monitoring the wells, EnCana doesn’t allow motorized vehicles to leave the roads in order to drive to a site. Employees must park on roads and walk in, though on rare occasions they can use an ATV.
Some environmental groups in the area remain skeptical about whether the mats will make much of a difference. “It’s a great idea to allow the soil horizons (layers) to remain,” says Linda Baker of the Upper Green River Valley Coalition, a nonprofit group that advocates for responsible drilling. But Baker worries that the extensive drilling in the Jonah Field makes any reclamation moot. And in the high, cold desert, restoring vegetation is difficult, she says. “Every time I go out there, I don’t see successful reclamation -- except the old, old stuff, and that’s only because it’s been left alone for 30 years.” Even so, Baker would like to see the mats used more extensively and by companies besides EnCana. In an area like Jonah, which is relatively flat, she says, it seems more of these mats could be successfully used.
At least one other energy company in the area is using wooden drilling mats. BP lays them around its wells in the Wamsutter Field, but doesn’t use them in Jonah because its sites there are too steep, according to BP spokeswoman Paula Barnett.
The reusable mats are more expensive than traditional reclamation (which involves replacing topsoil, reseeding and irrigating cleared land), says Teeuwen. The 12,000 mats EnCana now uses at Jonah cost the company over $10 million. (EnCana’s profits were almost $4 billion last year.) Still, he adds, EnCana is looking to use the mats in other regions -- wherever the topography can support them -- in order to soften its environmental impacts.
The author is a High Country News intern. © High Country News