New Texas Rule to Unlock Secrets of Hydraulic Fracturing A "fracking" operation near Big Wells, in which water and chemicals are injected deep underground to extract oil and natural gas. Starting Feb. 1, drilling operators in Texas will have to report many of the chemicals used in the process known as hydraulic fracturing. Environmentalists and landowners are looking forward to learning what acids, hydroxides and other materials have gone into a given well. But a less-publicized part of the new regulation is what some experts are most interested in: the mandatory disclosure of the amount of water needed to "frack" each well. Experts call this an invaluable tool as they evaluate how fracking affects water supplies in the drought-prone state. Hydraulic fracturing involves injecting water, sand and chemicals into underground shale formations at enormous pressure to extract oil and natural gas. Under the new rule, Texans will be able to check a Web site, fracfocus.org, to view the chemical and water disclosures. "It's a huge step forward from where we were," Amy Hardberger, an Environmental Defense Fund lawyer, said of the rule. Most fracked wells use 1 million to 5 million gallons of water over three to five days, said Justin Furnace, president of the Texas Independent Producers & Royalty Owners Association. A June study prepared for the Texas Water Development Board suggested that less than 1 percent of the water used statewide went into fracking. Oil and natural gas groups say such numbers show their usage lags well behind that of cities. But the data cited is a few years old, and drilling has since increased in places like the Eagle Ford Shale in South Texas. The amount of water used for fracking is "expected to increase significantly through 2020," according to the state water plan published this month. Dan Hardin, the water board's resource planning director, said water use for fracking was not expected to exceed 2 percent of the statewide total. But drilling can send water use numbers much higher in rural areas, Dr. Hardin said. For example, he projects that in 2020, more than 40 percent of water demand in La Salle County, in the Eagle Ford Shale, will go toward "mining," a technical term that in this case means almost entirely fracking. Until recently, no water went toward mining there. Researchers say predicting future water usage for drilling is tough, citing economic and technological uncertainties. Meanwhile, they want more data. Jean-Philippe Nicot, a research scientist with the Bureau of Economic Geology at the University of Texas at Austin and the main author of the water board's June study, noted that many drillers already reported water usage to the Texas Railroad Commission. The commission's new rule will be the first time water disclosure is required. Dr. Nicot would like to see more information about whether the water comes from aquifers or reservoirs, or has been recycled from other fracking operations. Texas also needs better information about what is in water that has been in the earth and comes up in a well in addition to oil or gas, said Mark A. Engle, a geologist with the United States Geological Survey's Eastern Energy Resources Science Center. That water can contain materials like grease and radioactive elements. "Texas ranks pretty much dead last of any state I've worked with for keeping track of that sort of data," Dr. Engle said.