State Expands Well Water Testing for PFOA in Londonderry

The New Hampshire Department of Environmental Services (DES) has expanded drinking water well testing for perfluorooctanoic acid (PFOA) to some streets in Londonderry.

“We have only identified seven active wells in the new area,” Town Manager Kevin Smith said, noting property owners within the radius will receive postcards from the DES to make sure they don’t miss testing any wells.

“We do have a small number of private wells located in the Londonderry area in that 1.5 mile radius we expanded to this week,” NHDES Public Information Officer James Martin said. “The DES has issued postcards to the residents in Londonderry, even ones we believe are likely on public water, because we want to double check with them. We have run into that a number of times where we thought a street was only served by public water, but there were some homes still on private wells.”

Streets in Londonderry that fall within the 1.5-mile radius around the Saint-Gobain Performance Plastics facility in Merrimack, which DES has identified as a responsible party for the water contamination of wells in Southern New Hampshire, include a portion of Litchfield Road, Acorn Drive, Sunflower Lane and Sandybrook Lane.

The DES announced on April 14 preliminary test results for groundwater samples taken at the Saint-Gobain facility were found to contain PFOA concentrations ranging from 280 parts per trillion (ppt) to 5,800 ppt.

The use of PFOA in manufacturing – as in the production of Teflon – can result in releases to air, water and soil. When PFOA is released to the air, it is readily absorbed to particles and settles to the ground, where the chemical can be transported to and contaminate groundwater.

PFOA, which is very resistant to degradation, was used at the Saint-Gobain facility dating back to at least 2001, according to the DES.

The U.S. Environmental Protection Agency (EPA) has identified PFOA as an “emerging contaminant.”

Earlier this month, the DES announced it would provide bottled water to residents whose wells tested over 100 parts per trillion (ppt) of PFOA.

Residents of Litchfield, Manchester and Merrimack whose wells have tested above 100 ppt of PFOA or are within the one-mile radius of Saint-Gobain are receiving bottled water, which Saint-Gobain has confirmed the company will pay for.

“At the moment we are not expanding bottled water to those folks (in Londonderry who live in the 1.5-mile testing radius), but we are expediting test results for the private wells in the 1.5 mile radius and if we start to see data with wells testing above 100 ppt, we will likely make a decision whether to expand bottled water to that area,” Martin said. 

DES officials said they will follow the data, testing outside their investigation area if they find further contamination.

A review of the preliminary soil sampling data found PFOA soil concentrations ranging from non-detect to 30 parts per billion (ppb), well below screening levels developed by the EPA of 16,000 ppb and Vermont’s residential soil screening level of 300 ppb.

The map with the expanded testing radius is available on the DES website at, where residents will also find information about PFOA, blood testing, water treatment options and updated water and soil test results.

Martin said there is also a form on the website that residents who live within the 1.5-mile radius may submit to the DES to request their well be tested.

Smith said the Town of Londonderry continues to monitor the DES’s ongoing investigation.

“The good news is we’ve been on top of it for weeks before Londonderry was even involved, so we were able to get out ahead of this,” he said.

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