The Hibbing Public Utilities Commission agreed to pay a $33,000 penalty for alleged air pollution violations and take measures to reduce noise and soot from its power plant, the Minnesota Pollution Control Agency announced Feb. 9.

The plant, located within Hibbing, burns coal and wood for steam and electricity. The smoke from its stacks violated limits on carbon monoxide and opacity for four quarters beginning in spring 2008, the MPCA found. The plant also produced too much dust. The agreement includes a proposal to modify the wood-fired boiler's steam vent silencer to reduce noise during start-up and shut down. Read the complete agreement at tinyurl.com/yfbk8nb.