A fire has been burning since Dec. 25. Workers from H.L. Zumwalt Construction Inc., which owns the land, have been using backhoes to pull the mulch pile apart. The company has had the mulch pile, which is about 400 feet long and 80 feet high, for 15 years. The company has a permit for the pile as part of a recycling operation.

A contractor has said that the fire could burn for more than a year if it is left to burn itself out.

"We are mostly concerned with the people who have chronic respiratory disease such as asthma and sensitive parts of the population such as children, elderly people, pregnant women or those with pulmonary or cardiovascular disease," Alsip said. "We want to stress that you don't have to be very close to the fire to have health effects from it, and people should limit their exposure to the smoke."