Duke Energy was warned in 1986 to have biennial inspections of pipe that leaked coal ash

Duke Energy was warned 28 years before February's spill that leaked as much as 39,000 tons of coal ash into the Dan River that "a stormwater pipe running under an ash dump was made of corrugated metal and needed to be monitored for leaks," Michael Biesecker reports for The Associated Press.

After the spill "Duke officials said the company didn't know that an underground section of the pipe was made out of metal, believing instead that it had been fully constructed of more-durable reinforced concrete," Biesecker writes. But records subpoenaed by federal prosecutors show that in 1986 Law Engineering Testing Co., which was hired by Duke to perform required inspections at the site, found that "part of this culvert is constructed of corrugated metal pipe which would be expected to have less longevity of satisfactory service than the reinforced concrete pipes."

The engineering company's report recommended that Duke "check on the pipe under the coal ash dump at least every six months," Biesecker writes. "The report said the inside of the pipes should be checked for leaks anytime there was a significant difference between how much was flowing in and how much was flowing out."

"In the days after the Feb. 2 spill, Duke issued public statements expressing surprise that the pipe wasn't made of corrosion-resistant concrete," Biesecker writes. Duke's lead lobbyist, George Everett, told state lawmakers at a Feb. 17 oversight hearing into the spill: "Originally, the media reported and we reported that this was a concrete pipe, the 48-inch one, because what we could see is right here at the river. The rest of this pipe, we discovered, as we worked from the other end, is a metal pipe — asphalt-coated metal corrugated pipe. That's the piece ... that broke." (Read more)