An administrative law judge upheld a $2,535 fine imposed on a Duluth construction company for improperly disposing of hazardous waste, according to a ruling made public this month. The decision by the Office of Administrative Hearings said the company, Builders Commonwealth, admitted to throwing away up to 7 pounds of chemical-soaked rags each month and dumping about 30 gallons of tainted water on the ground over two years. The chemical, trichloroethylene, used in some stains and thinners, is a carcinogen. The company claimed officials from a local hazardous-waste collection site deemed the material nonhazardous, but there was no documentation of this. The Minnesota Pollution Control Agency imposed the fine in 2009. Read the full decision here.