It was an unusual and unfortunate confluence of events: A larger-than-normal number of geese was making a later-than-normal migration over Montana when a snowstorm blew in at the wrong time and sent them soaring to the wrong place, reports the AP. The throngs of white birds splashed down in a 50 billion-gallon toxic stew in a former copper mine that is part of the nation's largest Superfund site. At least 3,000 of them died. Residents of the mining city of Butte say the snow goose deaths this fall were a wake-up call that raises broader questions about the site. They worry federal regulators aren't ready to prevent the heavily acidic, metal-laden water from contaminating other waterways and Butte's groundwater as the pit nears capacity.
When the site closed in 1982, the old shafts started flooding, sending tainted water into the Berkeley Pit. It's been slowly filling ever since. The liquid is expected to reach a critical level in 2023, and environmental officials are finalizing a plan for keeping it from polluting Butte's groundwater and a stream at the headwaters of the Columbia River basin. A water treatment plant now treats more than 4 million gallons of water a day that would otherwise flow into the pit, and the plan is for it to treat another 3 million gallons a day directly from the pit starting in 2023. Locals, however, say the plant has never handled so much water at once and no plan is in place to deal with an overflow. Officials say such concerns are "overblown." (Read more Montana stories.)