Ongoing PFAS Investigation - State and Local Updates

March 18, 2019: In response to the following letter, the Board of Selectmen has retained the firm of Wilcox and Barton to complete the Supplemental Site Investigation (SSI).
September 25, 2018: The Town has completed filing the following documents with the NH Department of Environmental Services:

March 2, 2018: In collaboration with the New Hampshire Department of Environmental Services (NHDES), the Town has initiated an investigation of soil and groundwater quality in the vicinity of the former and current Windham Fire Department properties located on N. Lowell Road and Fellows Road, respectively. The purpose of the investigation is to evaluate potential sources of per- and polyfluoroalkyl substances (PFAS) recently detected in local drinking water supply wells.

The analytical results of soil samples collected at the top of Fellows Road and adjacent to both the former and current Fire Station buildings exhibited varying concentrations of PFAS, including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). The highest concentrations were detected in soil collected from 0-2 feet below ground surface at the top of Fellows Road, where past fire-fighting demonstrations have been performed by the Windham Fire Department as part of Fire Prevention Week.

Groundwater samples collected during the investigation indicate that PFAS are also present in overburden groundwater in both areas. As shown in Table 1, PFOA and PFOS were detected at concentrations that exceed the NHDES Ambient Groundwater Quality Standard (AGQS) of 70 parts per trillion (ppt). The highest concentrations in overburden groundwater were detected in a monitoring well located next to the Bartley Building, which is downgradient of the former Fire Station and its leach field. These data suggest that historic fire-fighting practices and procedures commonly used at fire station properties has resulted in a discharge of these substances to the subsurface. It should be noted that the installation of overburden groundwater monitoring wells in the Fellows Road area was limited by shallow bedrock depths.

View the full test results for the North Lowell and Fellows Road area (test date January 15, 2018)

The Town’s environmental consultant, Nobis Engineering, Inc., will continue the investigation with the collection of drinking water samples from selected water supply wells in late February. A Site Investigation Report is expected to be submitted to the NHDES in April 2018.


December 8, 2017: The Town has completed its process to select an engineer to engage in conducting a site investigation. The firm of Nobis Engineering will begin its data collection phase as of Monday December 11, at which time they will be installing six (6) shallow monitoring wells. Three (3) wells will be located in the area of the former Fire Station on North Lowell Road, and three (3) in the area of the current Fire Station on Fellows Road. Further updates as to Nobis' progress will be provided once preliminary test results are known.


September 15, 2017: In May, the NH Department of Environmental Services advised municipalities that impacts to groundwater from PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate), collectively referred to as PFAS (per- and polyfluoroalkyl substances), had been identified in several NH communities. In use since the 1940s, these compounds have been widely utilized in industrial applications and in consumer products because of their properties to resist heat, oil, grease, stains, and water. In the environment, they are stable, persistent, and bioaccumulative. In 2016, the NHDES established "Ambient Groundwater Quality Standards" (AGQS) of 70 nanograms per liter (ng/L, equivalent to parts per trillion [ppt]) for PFAS.

In June, the NHDES conducted sampling and analysis of drinking water wells in many locations, including Windham's municipal center. The testing revealed the presence PFAS at the following Town buildings:

  • Fire Station (test date 8/4/2017): 124.00 ppt
  • Police Station (test date 8/4/2017): 3.00 ppt
  • Nesmith Library (test date 7/20/2017): 5.00 ppt
  • Town Hall (test date 6/7/2017): 24.00 ppt
  • Senior Center/Administrative Office (test date 6/7/2017): 72.00 ppt
  • Senior Center/Administrative Office (test date 8/4/2017): 96.00 ppt

In response to these findings, each facility exceeding the AGQS of 70 ppt is now restricted to bottled water only for consumption. As further testing is conducted, updated results will be posted here.

The Town is undertaking an aggressive response to this issue, continuing to monitor the sites in question and meeting with environmental consultants to establish a work plan as required by the NHDES to address this matter.

The NHDES has also advised that muncipalities having capped landfills must conduct similar groundwater testing as part of their annual monitoring. The Town is currently in the process of arranging for such testing at the old landfill on Marblehead Road, the results of which will be posted here.

We encourage residents to visit the following NHDES websites for more information on PFOA, PFOS, and PFAS and their ongoing investigation into their presence in New Hampshire: