MINNEAPOLIS (WCCO) – In the first debate in Minnesota’s hotly contested 8th Congressional District, the candidates talked guns, taxes and mining.

Congressman Rick Nolan debated Tuesday in Duluth with challengers Stewart Mills and Ray Sandman.

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The candidates sparred over whether it is environmentally safe to allow copper-nickel mines to open.

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Mining companies have been working for nine years to get government permission to open for business, despite concerns about damage to lakes and rivers.

Nolan, a Democrat, is running for re-election for the seat he won just two years ago.

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Mills, a Republican, is a first time candidate. Sandman is a Green Party candidate.