Chemical contamination caused by a former Dartmouth waste burial site has affected groundwater in a second private property in Hanover, New Hampshire.
In late August, a new test well was drilled 80 feet deep about a mile away from the Rennie Farm burial site.
Samples from that well show that the chemical 1,4-dioxane, a probable human carcinogen, had contaminated a second property in the Hanover neighborhood.
This time at levels three times the state allotted limit for drinking water. The state has not set a limit for groundwater.
Jim Wieck is the hydrogeologist working for Dartmouth. He says the new findings do fall in line with the expected path of the plume.
“We drilled along what we believe the direction of the migration of the plume is so we do expect to see 1,4-dioxane along that direction. It does confirm our model in that respect,” he said in a phone interview.
The contamination is left over from a lab burial site used in the middle of the last century to dispose of waste including animal carcasses from experiments involving radioactive isotopes.
At the end of August, workers were still excavating the site.
A year ago, the first neighboring family's well on Rennie Road tested positive for the chemical 1,4-dioxane, originating from this burial plot.
They were provided with bottled water from Dartmouth College.
Now, Dartmouth is setting up new test wells throughout the neighborhood stretching toward the Connecticut River.
“We understood that it would likely be detected off-site on the property that we're currently working on,” Jim Wieck said. “This is not a change in what we understood to be occurring.”
He continues: “I'm not saying other properties, I'm saying that that property specifically based on the data we had on site we understood it was quite likely that it would be present on that property.”
Wieck has reached out to the landowner, but the landowner says no one at Dartmouth has contacted him since the chemical was discovered on his 144-acre property.
The property owner — who doesn't live on the land in question — did not want to comment further about the contamination.
Maureen O'Leary is the director of Environmental Health and Safety at Dartmouth. She says though it took almost a year before Dartmouth looked for contamination beyond the first affected property, this is standard procedure for tracking a plume.
A map of new GZA test wells around the Hanover neighborhood where the chemical contamination is moving. The well-labeled GZ-26 is the latest well to test positive for the chemical 1,4-Dioxane.Credit GZA/Dartmouth CollegeEdit | Remove
“I think that doing the research and collecting the data is really not all that fast,” she said. “I think we're moving as fast as we can and we're putting lots of resources into this project and trying to find the ground water management zone and I think we're making great strides to get there.”
Dartmouth has spent $6.8 million on the cleanup to date. That's an additional $1.8 million over the totals the school provided last month.
In a 2011 Valley News article, the previous head of the Dartmouth cleanup said he expected the entire cost would be between $1 million and $2 million.
A pump and treatment remediation system has been approved to installed later this fall.
That system will not extend to the latest contamination found on the new site. However, Dartmouth has submitted an addendum to the state that would allow for further remediation.