pollution

Top California officials and environmental groups pledged legal action to stop the rollback.

Emissions standards are closely linked with fuel economy requirements because vehicles pollute less if they burn fewer gallons of fuel.

Scientists have only examined a small fraction of the estimated 8 million species on Earth.

Eskelsen also notes that the report holds the sites to an unfair water quality standard: the standard for drinking water.

Officials have yet to complete work including basic risk analyses on about 80 percent of abandoned mining sites on federal lands.

The report cites ongoing competition from cheap and cleaner-burning forms of energy, especially natural gas.

With about 4,000 wells proposed in an expansion of that project, it's likely that Badwater would see much greater volumes of discharged water.

The action lifts a construction ban on projects that could lead to air pollution and acknowledges that pollution control efforts have been effective.

On action days, oil and gas producers take steps such as reducing truck idling and limiting refueling.

About 1,200 vehicles in Wyoming were affected by the technology.