Lab tests show minnows died in airport runoff

MANCHESTER, N.H. (AP) – Minnows died off quickly when placed in samples of de-icer runoff that Manchester Airport lets seep into a nearby brook, according to tests conducted last year.

The results are contained in files The Union Leader obtained from the state Department of Environmental Services under New Hampshire’s Right-to-Know Law.

In a test performed last March, only 7 percent of minnows placed in the runoff survived after two days. The minnows also developed a reddish growth on their gills, even when the sample was diluted.

“A percent mortality of that amount can’t be good,” said Mary Kate Donais, a chemistry professor at Saint Anselm College who reviewed the results.

But Airport Director Kevin Dillon cautioned against reading anything into the data. He noted the Department of Environmental Services has said it must gather and analyze a third round of samples before drawing any conclusions.

“We’re not going to make judgments about inconclusive or partial data,” he said.

Last year the state started investigating Little Cohas Brook after residents complained about odors. At the time, Dillon acknowledged the propylene glycol used to de-ice planes was the likely source, but he said the chemical was environmentally friendly and that the airport was allowed to discharge 100,000 gallons a year into the environment.

Environmental officials are waiting for a break in the weather to gather more samples, said water quality biologist Paul Piszczek.

“That cold weather we had really kept things from moving and kept flows down,” he said. “So what we’ve got to do is sample during a runoff event, either a snowstorm, or rainstorm or melting water.”

He expects the sampling to take place later this month.