Dear EarthTalk: I hear there’s a greener form of fracking for natural gas and oil that uses carbon dioxide instead of water to access underground reserves. Is this really better for the environment? — Jason Burroughs, Erie, PA Hydraulic fracturing (known as “fracking”) is a method of causing fissures in underground shale rock formations to facilitate the extraction of otherwise inaccessible natural gas and oil. In a typical fracking operation, drillers inject a mixture of pressurized water and chemicals underground to fracture the rock and free up the gas and oil. Not widely employed in the U.S. until less than a decade ago, fracking has quickly become a major player in the U.S. energy scene. The resulting influx of cheap domestic natural gas — cleaner burning than the oil and coal it has replaced — is at least partly responsible for the fact that the U.S. has reduced its greenhouse gas emissions to the lowest levels since 1992. Fracking has been good for oil companies, the economy and even our carbon footprint, but it doesn’t come without environmental cost. A typical fracking operation pumps some five million gallons of water and chemicals underground to break up the shale. About half the water is removed during the oil and gas recovery process, leaving the other half underground where it can contaminate aquifers and degrade soils. Enterprising petroleum engineers have been hard at work trying to find ways to frack without water. One promising alternative involves using carbon dioxide (CO2) to break up the underground shale instead of water. “Fracking with carbon dioxide has a number of potential advantages,” reports Kevin Bullis in the MIT Technology Review. “Not only would it eliminate the need for millions of gallons of water per well, it would also eliminate the large amounts of wastewater produced in the process.” He adds that CO2 may also yield more natural gas and oil than water, given the dynamics of how it works underground. Also, CO2 used in fracking can be recovered and used repeatedly. And once a well is done producing, it can be sealed up, sequestering the CO2 underground where it can’t add to global warming. Researchers at the University of Virginia estimate that fracked sections of the Marcellus shale in the eastern U.S. could store over half of all U.S. CO2 emissions from power plants and other stationary sources over the next 20 years, with other shale formations providing significant additional storage. Right now CO2-based fracking is uncommon, given the abundance of water in our biggest fracking regions and the logistical challenges in transporting a compressible gas to well sites safely and cheaply. But as fracking expands into politically charged areas, or arid regions where water is scarce, waterless fracking could become more common. Already, nearly half of the fracked wells drilled across the U.S. in 2011-2012 are in water-stressed areas, according to the sustainability-oriented non-profit, CERES. And a recent study from the consulting firm Wood Mackenzie concluded that many of the countries with the greatest promise for developing shale oil and gas through fracking suffer from water shortages. Bullis says that one of the largest shale gas resources in the world is in China underneath 115,000 square miles of desert. “Piping in water would strain already tight supplies,” he says, but adds that China’s major use of coal-fired power plants means the country has plenty of CO2 it could be capturing and using. * * * * * Dear EarthTalk: Is there a way to get local communities involved in cleaning up waterways, like rivers, lakes, streams and creeks? — Rebecca, via e-mail Indeed, many of our local waterways have seen better days, thanks to decades of pollution. And cleaning them up and preventing further damage can be challenging, since much of the contamination has accumulated over time and results from what is known as “non-point source” pollution, which accounts for as much as 60 percent of the water pollution in the U.S. “When it rains, fertilizer from lawns, oil from driveways, paint and solvent residues from walls and decks and even pet waste are all washed into storm sewers or nearby lakes, rivers and streams—the same lakes, rivers and streams we rely on for drinking water supply, boating, swimming and fishing,” reports the non-profit Natural Resources Defense Council (NRDC). “Also, improper handling of materials around the house can lead to pollution.” According to NRDC, each of us can do our part to reduce this run-off pollution and thus help protect local waterways. For one, we can replace concrete and other hard surfaces around our homes with porous materials, so that rainwater drains naturally into the ground and not into pathways that lead it into waterways. We can landscape with native plants and natural fertilizers, and refrain from over-watering our lawns and gardens. And we can properly dispose of hazardous products (that is, not right down the drain), wash our cars at professional carwashes (where there are proper wastewater treatment procedures), recycle used motor oil, and use non-toxic alternatives for household chemicals whenever possible. Of course, there is only so much that individuals can do on their own. While preventing pollution at the source is important, many waterways have so much legacy pollution in them already that they need to be cleaned up directly—no small job and typically way beyond the scope of a few individuals. Some municipal, county or state governments might be inclined to help, but getting friends and neighbors involved first is a good way to demonstrate community support. Also, local businesses, non-profit groups, youth centers and schools are often looking for ways to get people involved in community service projects, so asking around town might be the best way to enlist dozens or more volunteers. Another way to get the ball rolling is to sign up with American Rivers’ National River Cleanup program. Individuals, organizations and anyone interested in conducting a cleanup on their local river can register with the program and get free trash bags as well as assistance with media coverage, volunteer promotion and technical support. The program has helped more than a million volunteers participate in thousands of cleanups covering more than 244,500 miles of waterways across the U.S. since it began in 1991. “These cleanups have removed more than 16.5 million pounds of litter and debris from America’s rivers and streams,” reports American Rivers. 2012 was the most successful year to date in the history of the program, with 400+ registered cleanups, 92,500 volunteers nationwide, 3.5 million pounds of trash removed from American waterways, and 39,000 miles of waterway cleaned. The group is hoping 2013 will turn out to be another record year for the program.