The change is happening so swiftly that regulators are racing to keep up and in some cases taking steps to make it easier for drillers to recycle.

Fracking operations require millions of gallons of relatively clean water. Each time a well is drilled, about 20 percent of the water eventually remerges, but it is jam-packed with contaminants from drilling chemicals and heavy metals picked up when the water hits oil. Until recently, that water was dumped as waste, often into injection wells deep underground.

Many companies, each using slightly different technology and methods, are offering ways of reusing that water. Some, like Schlosberg's Water Rescue Services, statically charge the water to allow particles of waste to separate and fall to the bottom. Those solids are taken to a landfill, leaving more than 95 percent of the water clean enough to be reused for fracking.

Other operators, such as Salt Lake City-based Pure Stream, offer two technologies a¿¿ one that cleans water so it can be reused in the oil patch and another more expensive system that renders it clean enough to be dumped into rivers and lakes or used in agriculture.

Todd Ennenga, Pure Stream's vice president of business development, said interest in the technology has doubled in the past year alone.

Some others tout methods that leave behind no solid waste at all, eliminating the need to transport anything to a landfill. A few companies insist they can frack without any water.

"It's really taken off," Ennenga said of recycling. Two years ago, he said, most operators were still vetting the different systems. These days, they have a plan and are saying, "We need to do this right now."

In Texas, the fracking boom began around 2009, just as the state fell into years of drought. Especially hard-hit were South and West Texas, where rock formations have proven to be rich sources of oil and gas. Residents who were told to cut back on lawn watering and car washing grumbled about drillers hogging water supplies.

If you liked this article you might like

What's Behind the Surge in Energy Stocks

Hillary Clinton Says Prosecuting Individuals is Key to Wall Street Reform