FAIRBANKS — The U.S. Environmental Protection Agency is investigating the source of unidentified “black dust” near the Aurora Energy power plant in downtown Fairbanks, following a complaint last year by a resident who lives nearby.

The EPA received a petition from the homeowner in May asking the agency to look at the suspected presence of coal ash in the area and the potential health risks it might pose. Other residents have complained about the issue to the Alaska Department of Environmental Conservation.

Dan Opalski, the director of environmental cleanup in the EPA’s Seattle office, said the agency visited the power plant in September and did a visual inspection of property in the surrounding area. Enough questions were raised during the visit to warrant a continuing investigation, he said.

Opalski said something resembling black dust was seen on the complainant’s property during the visit but that the agency hasn’t moved much past that observation in a cautious, slow-moving investigation. He said no conclusions have been reached about what the dust is, where it came from or any possible health risk it might pose.

Opalski said the next step in the process will be gathering more data through the collection and analysis of samples and a more thorough evaluation of the site.

That process is expected to occur this summer, but Opalski said a specific plan for its study hasn’t been developed. He also said residents in the area shouldn’t be alarmed at the prospect of an EPA investigation, since it’s too early to know if there’s a valid cause for concern.

“The nature of the work ahead is looking at potential problems and trying to understand if they’re real problems,” Opalski said.

Although the Aurora Energy power plant isn’t being eyed as the definitive source of the black dust, Opalski said the plant’s proximity will put it under greater scrutiny. He said the presence of other power plants in the area will also be considered.

“I think it’s fair to say in that environment there could be a number of things going on,” he said.

Aurora Energy President Buki Wright said the company plans to cooperate fully with the EPA during the process and that it is following local, state and federal rules about plant operation. In a statement, Aurora Energy said its plant improves emissions downtown by providing steam heat to buildings in the surrounding neighborhood, which offsets hundreds of furnaces.

“We’re in compliance with everything we need to be in compliance with,” Wright said. “We believe we’re operating conscientiously and are conscientious neighbors.”

Wright said the problem of coal ash escaping into the neighborhood used to be a bigger problem than it is today. He said Aurora Energy has gradually refined its system for hauling away ash, which is the residue from the coal that is burned to fuel the plant. Wright said the ash is mixed with water to reduce dust and that the trucks that haul it away are fitted with canopies to keep their loads from escaping.

The coal ash is typically used throughout the area as structural fill in place of gravel, Wright said.

Opalski said his office gets several similar air quality complaints a year throughout its administrative region, which includes Alaska, Oregon, Washington and Idaho. He said it’s too early in the process to speculate about what steps the EPA would require if the agency determined a pollution remedy was needed.

Contact staff writer Jeff Richardson at 459-7518.