Energy industry works to recycle hydro-fracking waste water
Billions of gallons of fresh water are consumed annually by natural gas wells that employ hydraulic fracturing to force underground rock formations to yield up gas trapped within. Fracking, as it’s known, is causing a boom in domestic energy exploration. It’s also raising environmental concerns about, among other things, the way it takes in fresh water from lakes, rivers, aquifers and municipal drinking water systems, and puts out water so contaminated with salt, heavy metals and other pollutants that it can’t be reused for drinking, irrigation, fracking or anything else and must be disposed of through deep injection wells.
Energy executives fear that without addressing environmental concerns, fracking could be headed for a rapid demise. “France and Belgium have permanently banned it,” says Chris Faulkner, CEO of Breitling Oil & Gas, an independent exploration and production company located in Irving, Texas. “And it has everything to do with water.”
Two major water issues concern critics. “One is the chemicals that go down the well and the fear that they will contaminate ground water,” said Faulkner. “The other is the water that comes back up.” To address the first, companies like Breitling are trying to come up with new formulations of fracking chemicals that won’t pose the risk of harming the environment. Companies that treat water from fracking operations to make it reusable are now seeing their own boom, as energy producers try to reduce the costs and environmental impact of existing ways of handling water generated from fracking.
Recycling water from fracked wells makes sense on several levels, according to Warren Sumner, CEO of Omni Water Solutions, an Austin, Texas, company that has developed a system to recycle the water. “Today the practice of disposing of water typically involves trucking it to a disposal well,” Sumner said. “There’s a lot of cost and collateral damage from that trucking process.”
The sheer volume of water a frack job consumes – about 5 to 10 million gallons per well – along with the usually remote locations of such wells, makes the challenge formidable. “We’re talking about 700 to over 1,000 truckloads just to carry away the water from a typical frack job,” Sumner said. “So the volume of trucking is enormous and the wear and tear on the roads is large. Everyone would like to reduce that.”
Natural gas is a relatively low-polluting fossil fuel that many see as critical to helping reduce America’s reliance on oil and coal. It’s also plentiful, with some estimates pegging domestic deposits as sufficient to supply U.S. energy needs for a century. It’s hard to get to, however, because those deposits are deep and the gas is trapped in shale rock formations.
Fracking, which pumps a mixture of water, sand and chemicals, at enough pressure to shatter underground rock formations, has stirred up a variety of environmental concerns. Flammable methane gas has been found in drinking water supplies near gas fields, for instance. Also, earthquakes, in such unlikely places as Ohio, that may have been caused by the use of deep injection wells to dispose of water coming back out of fracked wells.
Of the 5 to 10 million gallons of fresh water consumed by the typical frack well, an average of about 20 percent flows back up to the surface, where it must be disposed of. The flowback water is contaminated with salt, heavy metals and other pollutants, making it unsuitable for disposal in freshwater lakes, rivers and aquifers.
To date, much of this flowback water, as well as additional water that is produced from underground reservoirs along with the natural gas, has been disposed of by injection into deep wells. These wells are common and widespread in some areas, such as Texas where the Eagle Ford Shale formation has spurred one of the large fracking booms. They are uncommon in many areas such as the Northeast, where the Marcellus formation in Pennsylvania, New York and West Virginia is the nation’s biggest such deposit.
Disposal wells have come under scrutiny in the wake of a number of unusual earthquakes in some regions near deep injection disposal wells. One injection well outside Youngstown, Ohio, was closed after a series of small earthquakes struck the area beginning in early 2011. Thus, in many areas of the country, the primary method of disposing of contaminated frack water is becoming less viable.
Recycling can help greatly with this problem, says Yves Pollart, vice president with Rettew Flowback Inc. (RFI), a Lancaster, Pennsylvania, company that treats frack water so that it can reused for fracking. As is, upwards of 20 percent of water used for fracking is recycled, Pollart said. But much more could be.
Recyclers like RFI and Omni use trailer-mounted systems that apply several different treatment methods to contaminated flowback water, in order to return it to a state that is acceptable for reuse. The methods vary according to the contaminants in the water, which can be widely different depending on the underground environment, and on the needs of the fracking company. However, they include filtration and chemical treatment, along with computerized monitoring and management of the process.
The resulting water can be, in some cases, made as clean as drinking water. However, that’s not usually the goal. In order to be re-used for fracking, the water can still be too briny to be discharged into the freshwater system.
“It’s typically what we call clean brine,” Sumner says. “It’s devoid of objectionable materials like iron, magnesium, calcium, barium and strontium. But it still has salts in it such as sodium chloride and potassium chloride. We find that many operators prefer to leave those salts in it because that’s in their frack chemistry already. That way they don’t have to repurchase those salts.”
The treatment techniques are effective enough that recycled frack water can be re-used over and over again for future frack jobs. The savings in consumption of fresh water, potential pollution of underground water supplies, possible prevention of earthquakes caused by injection and financial benefits of treating water on-site so it doesn’t have to be trucked in or out, make recycling a highly attractive proposition for energy companies, environmentalists, regulators and transportation authorities charged with maintaining roads.
Among the challenges to increased recycling are getting frack companies to standardize their requirements for the cleanliness of water used for their procedures, Pollart said. There’s little doubt recycling is here to stay in the oil patch. The problem of dealing with contaminated flowback water will decline along with the number of active drilling rigs as the gas deposits are gradually tapped out. But it will be replaced by smaller but still significant amounts of similarly contaminated water naturally produced along with the gas from wells.
This “produced water,” as it’s known, will ultimately be dealt with by evaporating it and then disposing of the left over salt in landfills, Pollart said. But for the moment, the new techniques for recycling frack water appear to be effectively addressing some of the biggest concerns about fracking. Sumner said it will get better. He foresees a day when recycled flowback, treated produced water and more water taken from existing brine resources provides all the water frackers need. “We can get the industry to net zero withdrawals on fresh water,” he said.