The 2007 fire was probably the first for that area in 6,500 years, according to scientific evidence examined later, Higuera said. But the wait for the next big burn won't be nearly as long, according to the evidence gathered in the study.

The sewage pipes are protected from low temperatures with a heating system that runs on diesel. Throughout December and into January, several communities in the North Slope and Northwest Arctic have been scrambling for diesel, as well as gas and heating oil, essential to thaw pipes, heat homes and run snowmachines.