The Alexandria City Council hopes to establish a target date next month for closing the Mirant power plant, which has long troubled some local officials and residents who say its ashy emissions are a health hazard

Yet it remains unclear what, if any, legal authority the city has to shut down the plant, which is owned by the Atlanta-based Mirant Corp. Although the company has declared bankruptcy and owes the city $1.4 million in taxes, company officials say they have no plans to close the plant, according to Mirant spokesman Steven Arabia.

The plant -- replete with smokestacks and coal heaps -- sits on a prominent site in north Old Town overlooking the Potomac River and supplies power to the District and Maryland, but not Virginia.

Rich Baier, the city's director of transportation and environmental services, said at a City Council meeting last week that the city has limited legal authority over the plant's operations and that its best chance to shut it down is to seek state enforcement action.

"We need to realize what our limitations are," Baier said.

But council members argued that setting a target date for the plant's closure would send an important message to both the company and local citizens who have long complained about the potential health hazards from the plant's emissions, including the blackish soot that covers surfaces in their homes and yards.

Council member Joyce Woodson (D) said that the city needs to send a strong message to the energy company.

"We need to be very clear," Woodson said. " 'We don't want you here. . . . We want you out of here by a date certain.' "

But Arabia said that the company has no intention of closing the plant, which he called an important part of the region's power infrastructure.

The company is currently negotiating a new permit with the state's Department of Environmental Quality that will allow it to continue operating. The company violated its emission permit last summer and fall, according to the state. Over five months, the DEQ measured 2,129 tons of nitrogen oxide gases emitted by the plant, more than 1,100 tons over what the permit allowed. Arabia said that in its ongoing discussions with the state about the violations and the new permit, the company is disputing the state's reading of the initial agreement. Arabia said Mirant is in the process of installing new controls that will limit nitrogen oxide emissions by at least 15 percent. "People want additional emissions controls on the station, and that's exactly what we're doing," he said.

The city is urging the state to include increased pollution controls in its agreement with Mirant, expected to be finalized sometime this summer, and to conduct a comprehensive air quality study at the plant and surrounding neighborhoods. It also opposes allowing the company to swap or buy "clear air credits" from plants in other regions whose emissions levels are lower.

"Trading is a tried and true component of the Clean Air Act," Arabia argued, saying that trading credits allows greater pollution controls at Mirant's four Washington area plants, benefiting the whole region.

In addition to the gas emissions, neighbors who live near the plant have long been concerned about air quality. The city has asked that the state require Mirant to better control its coal ash to address "fugitive dust issues."

But Alexandria resident Elizabeth Chimento -- who joined forces with neighborhood activist Poul Hertel to investigate the plant three years ago -- said she is concerned that the city has not addressed the issue of the smaller particulate matter emitted by the plant, which is microscopic and can cause asthma and other respiratory problems, according to some environmental experts.

City officials said they have studied the particulate matter and found the levels in Alexandria to be similar to those found throughout Northern Virginia. These findings, the city said, were similar to conclusions reached by Jonathan Levy, an assistant professor of environmental health at the Harvard School of Public Health, who studied the issue at the city's request. Levy will present his findings at a public information meeting 7 p.m. Monday at the Lyceum, 201 S. Washington St.

Some neighborhood residents believe those studies are incomplete.

"We feel protection of health is being left in limbo," Chimento said. "The city is waiting for a possible exit when nobody knows when that might be. We want the plant cleaned up, and we don't see anything being done at this point that's going to protect the local population here in Alexandria."

Elizabeth Chimento of Alexandria points to dust on a door near the Mirant power plant. "We feel protection of health is being left in limbo," she said.Alexandria residents Elizabeth Chimento and Poul Hertel are worried that the city hasn't done enough about the smaller particulate matter emitted by the Mirant power plant, which sits on a prominent site in north Old Town.