There’s a lot of water to treat. Hydraulic fracturing requires between 3 million and 5 million gal of water per gas well. The water is combined with fracturing chemicals and a sand or ceramic proppant and then pumped into the horizontal branches of the well. The proppant props open fractures in the shale, allowing gas that has been trapped for eons to flow out. After fracking, roughly 35% of the water returns to the surface as flowback in the first weeks. Additional liquid known as produced water—a mix of fracking fluid and groundwater—comes up with the gas for most of the life of the well.
Hydraulic fracturing got its start in western states, where oil and gas drillers pump untreated wastewater into nearby wells driven deep into porous rock. For decades, deep-well injection has been the first choice for disposal because of its low cost. But the Marcellus areas of Pennsylvania and West Virginia have a geology that is not suited to deep-well injection. To dispose of the water off-site would require around 40 truck trips every day for weeks or months. That is costly, and energy companies can literally wear out their welcome when using local roads.
In contrast, the goals of wastewater treatment are to reuse, recycle, or reduce the water that comes out of the well. Chemical firms that specialize in water treatment such as Kemira and Ecolab’s Nalco unit; equipment makers including GE and Siemens; and service providers, both large and small, customize their offerings depending on the water’s contents and where it is destined to go. The main consideration in selecting technologies, all agree, is cost.
With prices for natural gas at a historic low of less than $3.00 per thousand cu ft, energy firms are compelled to select the cheapest legal alternative. “My biggest competitor is a hole in the ground,” says Mark Wilson, marketing director for unconventional gas at GE Power & Water. “We are looking for more energy efficiency and lower capital costs.”I think one of the few bright spots in the #chemjobs field has been Nalco, which has been hiring consistently over the last few years. Read the whole thing, especially if you're interested in learning about some of the actual environmental consequences of hydraulic fracturing.