Longform

Sucking Up Water and Sand in the Quest for Natural Gas

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In 2009, the University of Texas compiled a report for the Texas Water Development Board (TWDB) that focused on water use at industrial sand mining facilities, particularly because of the increase in the use of sand in fracking. Numbers are difficult to pin down because water reporting isn't mandatory but, by studying similar sand mining facilities around the state, the report found that roughly 600 gallons of water is used to wash one ton of sand. At most sand facilities, water is often recycled, sometimes as much as 94 percent. The 600 gallons per ton includes the recycled water.

Washing 2,700 tons of sand a day at 600 gallons per ton is 1.62 million gallons of water a day. To get a rough idea how much water 1.62 million gallons is, however, consider this: According to the U.S. Geological Survey, the average person uses roughly 100 gallons a day in the United States. Even with recycling, that's a number that worries people who live near EOG's mine since a large draw-down in the aquifer could affect all nearby wells. Many owners have already lowered pumps deeper into their wells to chase the falling water table.

After a public meeting about the sand mine in June at which residents of Cooke and Montague counties made their worries known, EOG issued a press release stating its plans to drill the mine's wells deeper down below the Trinity Aquifer into a zone of brackish water not suitable for drinking. Typical water wells in this area are around 200 feet deep; 700 feet down is a highly saline water. Of the first six water wells EOG drilled, according to state well reports, three are, in fact, below the aquifer. The other three are in the aquifer and EOG explains the latter will be used for drinking water on site and landscaping to prevent erosion. Plans for the total number of wells EOG will eventually need are unclear, however, and locals share rumors the mine might need as many as 40.

Highlighting the premium on the aquifer water, this expanse, including Cooke, Denton and Collin counties, was recently designated a priority groundwater management area (PGMA) by the state, meaning it is expected to experience "critical" water shortages now or within the next 25 years. Come drought or flood, water supplies are already tight in this region and getting tighter.

Experts familiar with the Trinity Aquifer in this area, while hopeful, are skeptical about EOG's brackish water plans. "The brackish water below the aquifer is very spotty," says the conservation district's Patterson.

UNT's Hudak expresses the same doubt: "Below the aquifer are tight rock formations that don't produce a lot of water."

Since these wells are being drilled in a PGMA, they will be metered, and beginning January 1, EOG will have to pay for the water it uses, even brackish water. The newly formed North Texas Groundwater Conservation District that will manage this area will have the right to permit EOG's water usage.

While using brackish water under the aquifer is preferred to using fresh water, the practice still has drawbacks. Not suitable for human consumption, the water also isn't good for the environment. With a massive holding pond of this highly saline water used for mining sitting over the aquifer in the outcrop zone near the banks of Mountain Creek, locals are worried about potential overflow into the creek and eventually the Red River less than a mile away.

When asked about possible overflow or spillage from the storage pond, EOG spokesperson K Leonard responded in a written statement: "The facility was carefully designed, engineered and permitted to prevent any runoffs into Mountain Creek."

Law professor Amy Hardberger, who has a master's degree in hydrogeology and has worked with the Environmental Defense Fund for Texas in both the energy and water programs, thinks using brackish water is a step in the right direction for oil and gas companies.

"My initial reaction is that the situation is definitely helped by the fact that they aren't using fresh water," Hardberger says. "The Trinity is both not particularly full and, more importantly, water often moves quite slow through it so such a large amount of pumping can create major draw-down issues for other users.

"Using water that isn't being used for drinking water is much better, assuming that there is no hydrological connection between the water-bearing units such that pulling from that one could somehow dewater the Trinity. As a general rule, this is a solution I have been pushing for a while."

Locals hope there's enough brackish water below the aquifer to sustain all of EOG's operations.

Comparatively, though, the water used in mining sand is a drop in the bucket compared with the amount used in fracking itself.

According to the Texas Railroad Commission, as of July more than 15,000 natural gas wells were over the Barnett Shale, which starts under the city of Dallas and stretches west and south covering 18 counties and 5,000 square miles.

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Lauren Drewes Daniels is the Dallas Observer's food editor. She started writing about local restaurants, chefs, beer and kouign-amanns in 2011. She's driven through two dirt devils and is certain they were both some type of cosmic force.