"Underused Drilling Practices Could Avoid Pollution"
"As environmental concerns threaten to derail natural gas drilling projects across the country, the energy industry has developed innovative ways to make it easier to exploit the nation's reserves without polluting air and drinking water.
Energy companies have figured out how to drill wells with fewer toxic chemicals, enclose wastewater so it can't contaminate streams and groundwater, and sharply curb emissions from everything from truck traffic to leaky gas well valves. Some of their techniques also make good business sense because they boost productivity and ultimately save the industry money -- $10,000 per well in some cases.
Yet these environmental safeguards are used only intermittently in the 32 states  where natural gas is drilled."Source: ProPublica, 12/15/2009