CHARLOTTE, N.C. -- Duke Energy responded to the heat wave by firing up all four boilers at the Riverbend Steam Station off Highway 16 in Gaston County near Mountain Island Lake on Friday.
And where there's fire, there's smoke.
"Really nasty looking smoke," said Sara Behnke (pronounced Binky), who lives in the Mount Isle Harbor neighborhood within eyesight of Riverbend.
Last year Sara and her neighbors paid little attention to the Riverbend plant.
"But now I'm watching it like a hawk," she said.
Duke Energy fits its newer coal-fired plants with expensive scrubbers to dramatically reduce pollution. But not some older plants like Riverbend.
"It's fired up today and now we have a code red ozone day today and we're burning coal on top of it," said Behnke. "So not a good respiratory day for Charlotte that's for sure."
It's not just air pollution that concerns neighbors and environmentalists. Duke Energy purchases some coal from mines, which use so-called "mountaintop removal," scarring the landscape in West Virginia. And the coal-burning process leaves behind tons of coal ash dumped in unlined ponds on site at Riverbend.
"It's concerning," said Cathy Chiappetta, who lives nearby. "Our children are outside. They're swimming. They're playing. They want to be part of the lake. And it's dangerous. "
Duke plans to shut down Riverbend by 2015. In the meantime, Sara Behnke's daughter Anna says there is something one person can do: conserve.
"Put our air conditioning a little higher than usual, well, hotter than usual," said Anna, a fifth-grader who spoke in favor of shutting down Riverbend sooner rather than later at Duke's shareholder meeting.
As Duke CEO Jim Rogers likes to say, the cleanest plant is the one the utility never has to build.