The firm that owns the North Carolina plant where a chemical fire has been burning out of control since Thursday evening was fined earlier this year by state environmental officials for unsafe practices. More than 30 local residents and emergency responders have been treated at area hospitals for respiratory distress and chemical burns, according to news reports.

The North Carolina subsidiary of The Environmental Quality Co., a privately held company headquartered in Michigan, was slapped with a $32,000 penalty in March by the N.C. Division of Waste Management for six infractions. They included failure to "maintain and operate the facility to minimize the possibility of a sudden or non-sudden release of hazardous waste constituents to air, soil or surface water which could threaten human health or the environment" and to "immediately carry out the provisions of the contingency plan whenever there is a release of hazardous waste or constituents which threatens or could threaten human health or the environment," according to the DWM's Web site.

EQ North Carolina is located near downtown Apex, N.C., a town of about 32,000 people located 10 miles southwest of the state capital of Raleigh. The facility stores and manages hazardous wastes, which under its state permit may include highly toxic heavy metals, solvents, pesticides and other industrial chemicals. (For an explanation of the various chemical codes listed in the permit, click here.)

About 16,000 people were ordered to evacuate, with no word yet on when everyone might be able to return home. The fire released a cloud of dangerous fumes over Apex, and subsequent rains are washing those chemicals into the surrounding ecosystem. State water quality regulators report that ditches on the property carry runoff to a small pond, which empties into a creek that ultimately flows into Wake County's Lake Benson, a popular recreational facility and habitat for wildlife including bald eagles and great blue herons.

EQ had a similar disaster at one of its Michigan facilities last year, the Associated Press reports. On Aug. 9, 2005, a fire broke out at the company's plant in Romulus, leading to the evacuation of about 2,000 people from their homes and sending more than 30 people to the hospital. Lawsuits against the company over that incident are still pending.