Hydraulic fracturing is increasing the availability of natural gas in the Marcellus shale region that runs through much of the Mid-Atlantic states west of New Jersey and into Ohio. Hydrofracturing involves pumping a mix of water and various chemicals, including biocides and surfactants into deep wells under high pressure to displace natural gas. Much of the hydrofracturing fluid is recovered, and the recovered fluid additionally includes brine, metals, and normally occurring radioactive material.