* Berkeley Pit is a defunct open-pit copper mine near Butte, Mont. It's been slowly filling up with water that is highly acidic and laced with metals. The EPA issued a cleanup plan in 1994, but it's still negotiating with companies over who is responsible for paying the bill. Meanwhile, residents are worried about their ground water, and environmentalists say the growing toxic lake provides a deadly attraction to migrating birds.
On a recent Saturday, Montana activists held a ''memorial'' for 342 Snow Geese who died in the pit during the fall migration.
* In Tacoma, Wash., city officials have had to pay nearly $30 million to settle lawsuits with the owners of apartments or homes located near a municipal landfill that has been the source of methane gas. The city also has spent some $54 million to clean up the dump, which is a federal Superfund site. Once the cleanup is complete, Tacoma hopes to sell this real estate to recoup some of its costs.
* Near San Jose, Calif., local officials and the United States Navy are sorting out how to prevent contamination at Moffett Airfield from endangering ground water. The former Navy airfield is no longer in use, but for years chemical solvents, paints, and other toxic materials were routinely used and then disposed of at what now is a Superfund site. Several hundred of the 1,290 most-serious sites on the National Priorities List are on military bases and other federal government property.