In 2009, after outcry from activists and neighbors and following instructions from congressional leadership, the Architect of the Capitol pledged to stop burning coal at the Capitol Power Plant unless absolutely necessary.

Three years later, the same activists and neighbors want to ban the plant from using coal at all. They took their concerns to a public hearing Monday night convened by the District Department of the Environment, where more than 20 speakers accused the plant of having a cavalier attitude toward residents and their health.

The critics are using as leverage the AOC’s pursuit of new permits to proceed with “cogeneration,” a process that will use a natural gas-powered turbine to produce the energy needed to run the plant itself; the steam will help heat the Capitol complex.

But the AOC contends that the new process will allow the plant to be weaned off coal in the near future. The AOC says cogeneration will “increase system reliability, improve efficiency and help save taxpayer money,” as well as “significantly reduce greenhouse gas emissions … [and] a reduction in coal use at the CPP.”

It will also allow the power plant to reach 100 percent natural gas use, whereas the current, 60-year-old boilers only allow that 90 percent to 95 percent of the time, the AOC said.

But the proposed permits to install two cogeneration units at the plant would not ban coal use at the plant, a key demand of the activists. “This plant has symbolic value,” one D.C. resident said. “If there is a single plant in this whole country, a [single] power source … that should get its act together … this is that plant.”

They have the backing of Ward 6 Councilman Tommy Wells. He wrote in a Nov. 17 letter to Stephen Ours, chief of the permitting branch in DDOE’s Air Quality Division, that the plant, which he said “emits more soot and smog forming pollution than any other pollution source in the District,” should not receive its requested permits if it “relax[es] air pollution standards.”

On Capitol Hill, Ana Unruh-Cohen, deputy staff director for House Natural Resources ranking member Edward J. Markey, D-Mass., has also expressed interest in the issue: She has spoken with both the AOC and the Sierra Club’s D.C. chapters, and encouraged a meeting between all concerned parties.

However, the DDOE believes that “the proposed permits are not the appropriate vehicle to ban coal usage at this facility” and it generally supports cogeneration as “consistent with the mayor’s vision for a sustainable DC.”

The AOC is already restricted in when it can burn coal at the plant: when “heating needs exceed the capacity of the natural gas pipeline currently serving the complex,” during “abnormally cold conditions” and in cases where “equipment outages on the gas boilers require a backup.”

These were the stipulations handed down in 2009, when Minority Leader Nancy Pelosi, D-Calif. — then speaker — alongside Senate Majority Leader Harry Reid, D-Nev., directed the AOC to switch to natural gas as its primary fuel source.

As long as the AOC is abiding by these instructions, the agency cannot technically be faulted by congressional leadership. AOC spokeswoman Eva Malecki said Tuesday that the agency is in compliance, though instances when the plant has to rely on coal “varies from year to year based on weather, equipment performance, maintenance schedules, etc.”

Cogeneration’s ultimate goal would be the end of coal use entirely at the Capitol Power Plant, Malecki stressed. Once the permits are granted, construction commences and all systems are “go,” there would be no reason to keep coal on the premises at all.

That process could take a few years, though, which isn’t enough for anti-coal activists in and outside the Capitol Hill neighborhood. There is currently no timetable in place for the DDOE to issue its decision. The AOC expects the Environmental Protection Agency, which is also issuing necessary permits for cogeneration to commence, to reach a verdict sooner.