"Efforts to reduce pollution of the Chesapeake Bay are starting to pay off, a major new study says, finding that despite weather-driven ups and downs, the 'dead zone' that stresses fish and shellfish every summer has actually shrunk, on average, in recent years."

"The Environmental Protection Agency on Thursday released the outlines of its long-awaited probe into whether hydraulic fracturing -- the unconventional drilling technique that's led to a boom in domestic natural gas production -- is contaminating drinking-water supplies. Investigators will try to determine the impact of large-scale water withdrawals, aboveground spills of drilling fluids, and the fracturing process itself on water quality and quantity in states where tens of thousands of wells have been drilled in recent years."

"Scientists from the National Aquarium and the Johns Hopkins University say they've found low but potentially harmful levels of toxic oil contaminants in the Gulf of Mexico months after the Deepwater Horizon well blowout was capped."

"Oak Creek - A large section of bluff collapsed Monday next to the We Energies Oak Creek Power Plant, sending dirt, coal ash and mud cascading into the shoreline next to Lake Michigan and dumping a pickup truck, dredging equipment, soil and other debris into the lake."

"NEWARK — The first steps in a Superfund cleanup of massive dioxin deposits in the Passaic River were unveiled by officials today."

"ELDORADO -- Gold prospectors chasing $1,600-an-ounce flecks in river bottoms east of Charlotte also might be sucking life out of the streams, experts say."

"The Interior Department plans to issue a proposal soon forcing companies to reveal the chemicals they use in the so-called fracking drilling process on federal lands, as the Obama administration responds to public safety concerns over the shale exploration boom."

"DALLAS -- Environmental groups have notified the Energy Futures Holdings Corp. and its subsidiary, Luminant Generation Company, that they intend to sue the company for more than 38,000 alleged violations of the Clean Air Act at two Texas coal-fired power plants."

"After a celebrated comeback from abysmal water conditions and high pollution levels in the 1970s, Lake Erie is regressing to the highest levels of phosphorous contamination in 40 years, a Great Lakes expert said on Thursday."

"The top U.S. environmental regulator on Thursday said her agency would soon comment on the proposed $7 billion Canada-to-Texas Keystone XL oil sands pipeline, adding she was concerned about emissions and potential leaks that could result from the project."