HARRISBURG, Pa. (AP) -- Companies drilling in the lucrative Marcellus Shale natural gas formation in Pennsylvania face a Thursday deadline to stop bringing salty, chemically tainted wastewater to riverside treatment plants as state regulators prepare to check for compliance in an effort to protect drinking water.
Many of the largest drillers say they have already stopped the practice and now either reuse nearly all of the wastewater that gushes from gas wells or truck it to Ohio for disposal in the approximately 170 underground injection wells in that state.
Some industry officials, however, say disposal alternatives for smaller drilling companies are certainly going to be more expensive and will be in short supply for a few months.
Louis D'Amico, president of the Pennsylvania Independent Oil and Gas Association, said a number of companies may even have to stop drilling temporarily until they get a plan in place.
"I think they're all scrambling to figure out what they're going to do about it," D'Amico said. "I think a lot of it's going to Ohio, but there's limits on the capacity that can be handled over there."
Since drilling companies began using high-volume hydraulic fracturing in earnest in 2008 to extract natural gas from the shale, they have taken millions of barrels of the briny waste to treatment plants that discharge into rivers where utilities also draw drinking water for hundreds of thousands, if not millions, of Pennsylvanians.
Amid rising concern over drinking water contamination, Gov. Tom Corbett's administration last month asked drillers to stop using the 16 treatment plants, which aren't equipped to remove all the pollutants from wastewater that gushes from gas wells.
The state's April 19 request was made after some researchers presented evidence that the discharges were altering river chemistry in heavily drilled western Pennsylvania in a way that had the potential to affect drinking water.
The request does not address Pennsylvania's multitude of coal-fired power plants, shallow-well drillers or other industrial sources that are also a major factor in high salt levels that can affect drinking water.
Since then, drilling companies have dramatically reduced the amount of wastewater going to three industrial treatment facilities in western Pennsylvania that were on the list of 16, the plants' owners said Tuesday.
One company that has used the wastewater treatment plants, Chevron Corp. subsidiary Atlas Energy, said it will stop the practice by Thursday.
"In the near term, we will use a combination of expanded water reuse in our operations and underground water injection," Chevron spokeswoman Margaret Cooper said in a statement. "Chevron expects to be able to reuse 100 percent of all of Chevron-produced water by the end of 2011."
A spokeswoman for the state Department of Environmental Protection said the agency will take steps to verify that the practice stops as of Thursday. But the spokeswoman, Katy Gresh, said the agency did not want to reveal how it would do it.
In the meantime, the U.S. Environmental Protection Agency has asked the DEP to strengthen its request into one that is legally enforceable, and it asked six of the most active companies drilling in Pennsylvania to disclose by May 25 how and where they dispose of or recycle drilling wastewater.
In the second half of 2010, drillers reported that they generated about 5.4 million barrels of wastewater, and of that brought about 2.8 million barrels to treatment plants that discharge into rivers and streams, about 460,000 barrels to underground disposal wells, and about 2 million barrels to plants that treat the water, but do not discharge into waterways.
Some companies, like Range Resources Corp. of Fort Worth, Texas, or Chesapeake Energy Corp. of Oklahoma City, reuse most of their wastewater after cleaning it on-site by running it through a system of portable tanks and filters before mixing it with fresh water to prepare it for a new drilling job.
Tom Tomastik of the Ohio Division of Mineral Resources Management said he does not think the state's underground disposals wells have the capacity right now to replace
Depending on the actual volumes that are being disposed of in the POTWs in PA at this time, we may not have the total needed injection capacity right now. I have been told there is between 24,000 to 34,000 barrels per day disposed in the PA waste water treatment plants. We could not handle that much extra with our current capacity. I am getting a huge interest in the drilling on new Class II injection wells and with the drilling of new injection wells; we would be able to handle the additional disposal capacity. It would, however, take at least a few months to get these injection wells drilled and on line.