"Average lead levels at [Chicago's] Perez Elementary School were at or above federal limits during three three-month periods in 2010, the data show."

Minnesota's Pollution Control Agency is trying to address the impact of dissolved chlorides in Twin Cities lakes -- road salt harming aquatic life. It may require changes in what it means to be a good neighbor in the snowy state.

"The federal government has agreed to step up its efforts to force freighters sailing on the Great Lakes to begin treating their biologically contaminated ballast water discharges like any other industrial pollutant."

"Green roofs have become increasingly popular in the United States as a way to beautify and insulate buildings and reduce heat pollution in urban areas, but last week one drew attention for a far different reason: it collapsed."

"Fast-growing interest in natural-gas drilling could create a flood of cash for Ohio cities eager to treat wastewater used to coax the gas from deep inside Utica and Marcellus shale. But what's good for the cities might be bad for the state. The process could pollute Ohio streams and rivers, environmental officials say."

"The Great Lakes region, the world's largest freshwater system, could face local water shortages in the Chicago and Milwaukee areas due to increased demand and environmental changes, the U.S. Geological Survey said on Monday."

"Over the past three years, the Gary Sanitary District has discharged at least 6.8 billion gallons of raw and partially treated sewage to the bacteria-impaired Grand Calumet River and the flood-prone Little Calumet River, according to a Post-Tribune analysis of state data."

"The state of Minnesota is suing 3M Co. over its disposal of chemicals previously used to make Scotchgard and other products."

"In the fight over proposed mining projects in northern Minnesota, a new player with a surprising amount of clout has emerged -- wild rice."

"A federal judge [Dec. 2] rejected the request of five Great Lakes states for a preliminary injuction that would force the U.S. Army Corps of Engineers and the Metropolitan Water Reclamation District of Greater Chicago to keep invasive Asian carp out of the Great Lakes."