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Dartmouth Informs Neighbors of Cyanide Finding

Valley News Staff Writer
Published: 9/12/2017 12:14:27 AM
Modified: 9/12/2017 12:14:32 AM

Hanover — Dartmouth College officials say they have detected cyanide in treated water from Rennie Farm, the former laboratory dump site near Hanover Center, but that the readings were likely an anomaly — skewed by a deactivated pump.

Dartmouth for months has been running a system of pumps and filters to remove contaminants from groundwater around the rural hillside where lab animals were interred about 50 years ago.

In August, officials sampled water that had been treated and discharged from the system and found that it contained “a low concentration” of cyanide, a naturally occurring toxic compound.

The Centers for Disease Control and Prevention say cyanide is a “rapidly acting, potentially deadly chemical” that prevents the cells of the body from using oxygen and has its most critical effects on the heart and brain.

Jim Wieck of GZA GeoEnvironmental, the national environmental contractors handling Dartmouth’s cleanup, said the finding was an “anomaly.”

“It’s not consistent with the other data that we’ve collected so far,” he said in a telephone interview on Monday.

The cyanide appeared only once and at a concentration of 6 parts per billion, which is slightly above the discharge limit of 5.2 ppb established by the federal permit that governs Dartmouth’s treatment system, but far below the state of New Hampshire’s groundwater quality standard of 200 ppb.

College officials attempted to isolate the cause of the cyanide reading by restarting a pump that had been deactivated for maintenance during the initial test. They then sampled each individual pumping well for cyanide, yielding negative results.

This led administrators and their environmental contractors to conclude that the deactivated well had led to artificially high concentrations of cyanide in samples.

“It’s out there at very low levels,” Wieck said of the chemical, which is known to be produced by fungi and such plants as white clover.

The more wells that are running, the less likely a sudden spike in cyanide concentration is likely to skew readings, Wieck said.

On the other hand, if one well is deactivated, “under those circumstances the concentration from one well is going to have more of an influence on the concentration that you’re getting,” he said.

Cyanide is “not a known site contaminant at Rennie Farm” and this discovery poses “no danger to human health,” college officials said in a recent email to residents.

Dartmouth started pumping again on Aug. 22 with permission from the New Hampshire Department of Environmental Services and the federal Environmental Protection Agency.

Tests of treated water afterward were negative for cyanide.

State officials concurred with the college that the cyanide was not likely to be a concern.

“As a one-time detection that arose when one of the main extraction wells was not in service, the detection was not a major concern, but would be studied further if it persisted,” James Martin, a spokesman for NHDES, said in an email Monday.

State officials in August also issued a groundwater management permit lasting until 2022 that specifies how the college’s cleanup will be run.

The purification system was put in place to remove a chemical called 1,4-dioxane, a solvent component found in industrial use and household cleaning products, from the site where thousands of pounds of test animals were buried in the 1960s and ’70s.

College officials have said the animals were used in radiological experiments, and the 1,4-dioxane is believed to have been a component of scintillation fluid.

The fluid is used to measure small amounts of radionuclides.

An underground “plume” of the substance was set in motion by a 2011 excavation of the site, and now the pumps will clean it up, state and college officials say.

Rob Wolfe can be reached at or at 603-727-3242.

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