The rule-breakers mishandled hazardous waste, allowed runoff to pollute waterways, and sent too much mercury and particulates into the air.

These are some of the violations tagged by the Minnesota Pollution Control Agency in July, August and September.

I looked at the MPCA's third-quarter enforcement actions for air, water, toxic waste and other violations. The agency issued orders against 64 businesses and individuals and assessed $710,274 in penalties. This is up significantly from the previous quarter, when there were 46 orders totally $347,236 in penalties.

Following are the 10 violators with the highest fines. The first six agreed to the agency's orders. The others were issued unilateral orders. All were ordered to comply with laws.

1 Biofuel Energy Corporation, doing business as Buffalo Lake Energy LLC, Fairmont, fined $285,000 for air and water quality violations.

The company's treatment system sent water that is toxic to aquatic life into a nearby creek. It didn't report spills and discharges. It violated air pollution limits for particulates and nitrogen oxides.

2 Cook County and Grand Marais Joint Economic Development Authority, KGM Contractors, Grand Marais, fined $120,000 for stormwater violations.

A construction project at Cedar Grove Business Park in Grand Marais allowed sediment to wash into wetlands and waterways.

The parties agreed to pay a $40,000 fine and spend $80,000 to remove sediment from a culvert along the Gunflint Trail and stabilize 330 feet of ditch nearby.

3 Bimeda Inc., Le Sueur, fined $65,841 for hazardous waste violations.

More than a ton of hazardous waste was stored in open containers, not labeled or disposed of properly. Flammable materials were stored without a permit. Bimeda, a maker of animal pharmaceuticals, agreed to pay a $7,000 fine and spend almost $60,000 to upgrade their lighting and mechanical systems to make them more energy efficient.

4 CHS Inc., doing business as Eastern Farmers Elevator, Jasper, fined $45,000 for air quality violations.

The grain elevator didn't have a dust collection system and was operating without an air emissions permit. Particulate emissions were too high.

5 Northern Metals LLC, doing business as Northern Metals Recycling, Minneapolis, fined $15,000 for air quality violations.

Tests conducted in 2009 showed that particulate emissions from their metal-shredding facility were 204 percent higher than allowed and mercury emissions were 32 percent higher.

6 Northshore Mining, Silver Bay, fined $11,750 for air quality violations.

The taconite plant was sending too many particles into the air. One source was identified as a malfunctioning anti-pollution device called a furnace "discharge scrubber." Another source was a vent in a coal-transfer and storage area.

7 3M, Cottage Grove, fined $10,000 for hazardous waste violations at its incinerator. $1,389 of that was forgiven.

The facility stored too much waste in a lab. Some containers were resting on cracked flooring or were not sealed and labeled properly. Contractors lacked training.

8 Michael Stamer, Willmar, fined $8,581 for solid waste violations.

Stamer was burning solid waste, including oil filters, without a permit. He also had citations related to the mishandling of filters.

9 Daryl Harberts, doing business as Daryl's Service, Rushmore, fined $8,350 for above ground storage tank violations. $600 of that was forgiven.

Tanks and storage areas were not adequately equipped for small spills or large-scale containment.

10 James Pella, Pierz, fined $7,874 for solid waste violations.

Pella was burning solid waste, including tires, without a permit. The fine has been referred to a collection agency.

Hard Data digs into public records and puts a spotlight on rule breakers in the Twin Cities and Minnesota. Contact me at jfriedmann@startribune.com.