02/04/2013 03:26 pm ET Updated Apr 06, 2013

Frack Tracks: Safer Fracking Fluids, Water Crisis Worries And Drilling In The Desert

Welcome again to my blog, Toxic Tracks. Please send along any feedback or ideas for environmental health topics via email or Twitter.

With anti-fracking activists widely hoisting jugs of dirty water in protest of what they say is a toxic industry, natural gas companies are naturally looking for ways to ease public concerns. Their latest effort: nontoxic fracking fluids. As AP reported yesterday, energy giant Halliburton has developed a concoction that uses only food-industry ingredients.

In hydraulic fracturing, or fracking, large volumes of water, sand and chemicals are shot thousands of feet underground to crack open shale rock and extract its embedded natural gas. The potential contamination of drinking water by this mix and its flowback is among the most controversial aspects of the natural gas production process.

Environmental groups are cautiously optimistic about Halliburton's new brew, but highlight some caveats. For one, the safer fluid is more expensive. Also potentially limiting its use by industry is the "tremendous variation in the type of shale rock in different parts of the country," which forces drillers to use different fluids -- even within the same state, reports the AP.

As experts and advocates further note, water contamination concerns with fracking go beyond the chemical-infused injection fluids. Fracking wastewater may also carry heavy metals and radioactivity released from the shale itself.

Still, generally missing from the debate over water contamination with fracking is what may be happening to any deep water reservoirs at the depths fracking fluids are injected into gas-rich shale and waste water is reinjected into disposal wells.

Propublica posted an interesting story last week concerning Mexico City's plans to draw drinking water from a mile-deep aquifer. The article goes on to makes a cautionary connection: "America is poisoning wells it might need in the future."

U.S. environmental regulators have long assumed that reservoirs located thousands of feet underground will be too expensive to tap. So even as population increases, temperatures rise, and traditional water supplies dry up, American scientists and policy-makers often exempt these deep aquifers from clean water protections and allow energy and mining companies to inject pollutants directly into them.

Propublica interviewed Mike Wireman, a hydrogeologist with the EPA who also works with the World Bank on global water supply issues:

"Depth in and of itself does not guarantee anything -- it does not guarantee you won't use it in the future, and it does not guarantee that that it is not" a source of drinking water, he said.

Turns out, some of the U.S. regions most fervently drilling for natural gas are the same regions on the verge of a drinking water crisis, namely parts of Texas and Colorado.

Also worth a read is a piece in yesterday's New York Times about Colorado communities fighting against natural gas leases on public lands.

Here, amid dozens of organic farms, orchards and ranches, the federal government is opening up thousands of acres of public land for oil and gas drilling, part of its largest energy lease sale in Colorado since Mr. Obama took office. In all, leases for 114,932 acres of federal land across Colorado are being auctioned off next month -- a tiny piece of what Mr. Obama lauded during last year's campaign as a historic effort to increase domestic natural-gas production.