CHARLOTTE, N.C. -- As Duke Energy pitches Charlotte on the idea of moving millions of tons of coal ash from the closed Riverbend Steam Station on Mountain Island Lake to use as fill dirt for construction at Charlotte Douglas Airport, an expert on the effects of coal ash is urging caution.

The airport in Asheville is already using coal ash as so-called structural fill -- fill dirt placed in black plastic liners to build runways.

But a scientist who has studied the effects of coal ash for decades says those liners can and do leak.

They are designed to allow a certain amount of leachate and seepage and drainage to go through, said Dennis Lemly, a biologist at Wake Forest University.

Lemly has studied coal ash toxicity in fish and wildlife since 1978. He has published research showing one element in coal ash, selenium, causes birth defects in fish. And that s not all.

There is a variety of toxic effects in humans, including birth defects and deformities, so the variety of toxic effects is the same whether it s a fish, a bird, a mammal or a human, Lemly said.

He says even though airports install liners, coal ash could leak and enter groundwater, flowing underground to wells or surface water.

We don't have any information on the storage characteristics or the performance standards for these fills in any way shape or form, and in fact, many of these landfills and structured fills are unregulated and unmonitored, said Lemly.

Dr. Lemly says state lawmakers and Charlotte city officials have not asked him to testify, but he would urge caution before dumping tons of coal ash where it could have contact with groundwater.

I would say stay away from it just because the risks we see out there outweigh the benefits in terms of long term hazard to fish and wildlife, Lemly said.

Charlotte s acting aviation director and assistant city manager have gone on record expressing concerns about the risks of coal ash at the airport but city staff continues to study the issue before making a recommendation to city council.

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