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A Challenge For Texas Oil Drillers: Billions Of Barrels Of Wastewater

The number of drilling rigs working in Texas has dropped along with the price of oil. But what hasn’t diminished is concern over a by-product of drilling: billions of barrels of waste-water a year. Where has it all gone?


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In the Eagle Ford Shale in South Texas, roads are busy with tanker trucks. Many are hauling wastewater from drilling sites to disposal wells.


A surge in drilling has brought something besides billions of dollars’ worth of oil & gas up from subterranean Texas: it’s generated billions of gallons of polluted water. 

It’s a mix that contains mostly naturally-occurring saltwater but also water used in the drilling process that’s tainted with chemicals and hydrocarbons. Statewide, drilling is producing an estimated 6 million gallons of wastewater a day, about as much as a small city might generate.

Technically it’s considered non-hazardous but you can’t just pour it down the drain or into streams. Instead, it’s mostly being pumped back into the ground using what are called disposal wells. But where’s a good place to do that?

The issue was part of a dispute that ended up in the Texas Supreme Court.

“If you have chemical wastes, non-hazardous, where can you store it?” said Craig Enoch, a lawyer for Environmental Processing Systems.

The company was storing — or disposing — of wastewater down an 8,000 foot well east of Houston in Liberty County. But the facility was next to rice farms and the farmers said the waste might migrate under their farmland which they said wasn’t fair to them unless the company would pay them. The court eventually ruled the company didn’t owe the farmers anything.

So it was case about money and land rights. But with the talk of the underground migration of wastewater, what about the environment?

“Right now we don’t know is what the real risk is. We don’t really have a way of quantifying it,” said Paul Bertetti, a geologist at the Southwest Research Institute in San Antonio.

Bertetti says the state has failed to maintain a database of disposal well mishaps so estimating a risk is impossible. And there have been problems. A decade ago near Midland, wastewater from a disposal well migrated to a nearby abandoned oil well bore. The waste flowed up the old well bore until it reached an aquifer, polluting it according to the state’s oil & gas regulator, the Railroad Commission of Texas.

Then, just a few years ago in Dimmitt County in South Texas, wastewater being pumped into a disposal well traveled over a quarter mile underground where it too, reached an old, abandoned oil well. The wastewater went up the old well bore and began spewing out on to ranchland.

“The problem is these alternative pathways that could potentially lead to contamination either at the surface or underground,” Bertetti told News 88.7.

Bertetti makes the situation sound like the proverbial ticking time bomb because there are now over 7,000 disposal wells across Texas. And there are thousands more of the of old, abandoned oil & gas wells, often in the same area but sometimes unmarked.

“It is a problem in that there is potentially a lag time,” said Bertetti. “There is a lot of uncertainty with respect to when something might occur, where it might occur.”

The state has rules that say before a disposal well can be used, the operator must make sure there are no faulty old oil wells within a quarter mile…or in some areas, a half mile. Bertetti says he’s not sure that’s a big enough safety zone considering how the waste can migrate.

Last month, in the Texas legislature a House committee heard testimony about ways to reduce the problem by reducing the amount of wastewater. Some drillers are purifying the water at oil & gas well sites and recycling it.

“It isn’t a trivial thing to do. Because sometimes you have very bad water that goes in the ground,” testified Cal Cooper, a water treatment expert with Apache Corp., a Houston-based driller.

Cooper said the water can contain hydrogen sulfide, a dangerous gas. But he seemed optimistic that drillers would find ways to increase the recycling of drilling wastewater which currently is seldom done in Texas.

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