MINNEAPOLIS — Legislation from two Minnesota congressmen which allows for expanded mining in northeastern Minnesota has caused broader environmental debate in the U.S. House and divided the state’s congressional delegation.

The House Tuesday passed DFL Rep. Rick Nolan’s bill that finalizes a land exchange between the U.S. Forest Service and PolyMet Mining. The exchange advances PolyMet’s proposed copper-nickel mining project in northeastern Minnesota. Environmentalists say copper-nickel mining is more harmful to the area’s waterways than the existing taconite mines.

Protecting the region’s environment also spurred lively debate Wednesday when Republican Rep. Tom Emmer defended his legislation that requires congressional approval of any move by federal officials to withdraw government-owned land from mining. A vote on Emmer’s bill was delayed until Thursday.