As Members and top Capitol Hill officials work to create a new long-term master plan for the Capitol complex, they also are grappling with what to do about the coal-burning Capitol Power Plant.

The future of the power plant — the century-old facility provides the steam and chilled water that heats and cools the Capitol complex — was perhaps the centerpiece topic when Members and officials met during a Transportation and Infrastructure subcommittee hearing on Tuesday to talk about that master plan.

After all, the discussion before the Subcommittee on Economic Development, Public Buildings and Emergency Management dealt with the future of the campus itself, which Speaker Nancy Pelosi (D-Calif.) has declared will become as green as possible.

There’s little doubt that the power plant is a major producer of carbon emissions — Del. Eleanor Holmes Norton (D-D.C.) labeled it “the greatest polluter in the District of Columbia” — but getting rid of it isn’t that simple.

As acting Architect of the Capitol Stephen Ayers told Members, switching the complex’s cooling and heating needs from a centralized facility to each individual building would take years and could cost about $2.5 billion. In his written testimony, Ayers labeled eliminating the power plant “impractical and cost-prohibitive.”

“Existing, centralized heating and cooling systems have been studied and proven to be most cost-effective for a large campus such as the Capitol complex,” he said.

Instead, the AOC is focusing on improving the plant’s environmental efficiency. Ayers told the panel that his agency has made strides to increase the plant’s efficiency in recent months, including the ongoing expansion of the West Refrigeration Plant.

The plant’s expansion is designed to help provide heating and cooling needs to the Capitol Visitor Center, which is slated to open in November. But it is also designed to upgrade refrigeration systems to increase overall efficiency, including by using environmentally friendly 134-A Freon, he said.

The plant uses a mixture of fuels —natural gas, oil and coal — depending on cost, Ayers said. Only low-sulfur, low-ash coal is now used, Ayers said.

“The ability to burn three fuels at the CPP assures reliability, provides flexibility, and ensures some protection against rapidly rising fuel costs,” he testified.

Chief Administrative Officer Dan Beard, who is overseeing the Green the Capitol Initiative, admitted that the plant is perhaps the biggest hurdle in making environmental improvements on the Capitol campus. But Beard added that he now is resigned that the plant isn’t going away.

“I think we have to make the best of a bad situation,” he said. “I think the centralized system that we have is very inefficient, and the best thing we can do is make it as efficient as we can.”

As Members debate the future of the power plant, the facility finds itself alongside other government facilities caught in the battle over how air emissions should be regulated.

One environmental expert warned Members at the hearing that the plant is not in compliance with regulations that require facilities that produce hazardous air pollutants to obtain a specific permit setting limits on toxic emissions.

AOC officials refuted those claims, calling them inaccurate and pointing to the fact that the power plant operates under a valid Title V Environmental Protection Agency permit requiring emissions monitoring and reporting.

Earthjustice staff attorney James Pew testified that the plant’s steam-generating boilers produce a range of toxic metals and acids, which are particularly dangerous and can cause an array of health problems.

The plant’s current permit does not contain limits or create a schedule for meeting limits on emissions of some of these pollutants, Pew testified, adding that a lot of that is the EPA’s fault.

The Clean Air Act of 1990 required the EPA to issue standards for hazardous air pollutants generated from boilers by November 2000, Pew said. But the EPA didn’t issue standards until 2004, which were “hopelessly defective” and failed to establish standards for the majority of boiler-emitted pollutants, Pew added.

Those standards were declared unlawful by the U.S. Court of Appeals for the District of Columbia in June 2007. And when the D.C. Circuit issued its 2007 ruling, responsibility fell to the District of Columbia and AOC to submit a special permit application requesting limits on the plant’s emissions of hazardous air pollutants.

The AOC has not done so, Pew said. (Neither have a slew of other government and privately run plants, he admitted.)

But AOC spokeswoman Eva Malecki said that the Title V permit requires the power plant to report emissions to the EPA and the District of Columbia on a semiannual basis, which it does.

“The CPP is in full compliance with the Clean Air Act of 1990,” Malecki wrote in an e-mail. “EPA Region III officials have inspected and verified CPP compliance.”

Other topics tackled on Tuesday:

• Members discussed the need to fund $1.4 billion to tackle a backlog of deferred maintenance and capital renewal projects. Committee Chairman James Oberstar (D-Minn.) suggested that the committee draft a long-term authorization bill that would address the backlog.

• Capitol Police Chief Phillip Morse told Members that the department will present its plans for a new radio system to the Capitol Police Board by next week. The department’s 25-year-old system is not interoperational, meaning that the Capitol Police are not able to communicate with other police agencies via radio, which could be a serious issue during a major emergency if phone lines go down.

• Beard updated the panel on the Green the Capitol Initiative. The House is hoping to be carbon neutral by July 4, he said.