"Colorado's intensifying oil and gas boom is taking a toll on soil — 200 gallons spilled per day seeping into once-fertile ground — that experts say could be ruinous.
The state's approach has been to try to compel companies to excavate and haul the worst muck to landfills.
But with support from state regulators, oil companies increasingly are proposing to clean contaminated soil on site using mixing machinery and microbes. This may be cheaper for the industry — and could save and restore soil.
But it is not proven."