Information for Kensington residents and affected property owners about environmental testing, PFAS monitoring, and ongoing work at Unitil’s Kensington facility.
Unitil has been conducting environmental testing at its facility located at 114 Drinkwater Road in Kensington, New Hampshire since early 2021 in coordination with the New Hampshire Department of Environmental Services (NHDES).
The facility has been used for electrical equipment storage and distribution since the 1950s. Unitil moved its operations to Exeter, New Hampshire in November 2020 and reopened in 2024 as an operations training facility.
The current work includes testing soil, groundwater, and drinking-water wells to better understand where certain substances are present and whether they extend beyond the property. NHDES has directed Unitil to monitor 22 nearby properties as part of this effort.
What's Happening Now
The purpose of the current work is to continue evaluating environmental conditions, monitor nearby properties, and provide NHDES with the information needed to determine whether any additional action is appropriate.
- November 2025: NHDES directed Unitil to develop and implement a PFAS monitoring program involving 22 nearby properties.
- June - August 2026: Unitil worked with NHDES to finalize the sampling approach.
- August 2026: PFAS monitoring began.
PFAS was first identified in 2019 during testing required by NHDES for public water supply systems. PFAS stands for per- and polyfluoroalkyl substances and is a group of human-made chemicals that can remain in the environment for a long time. Certain types of PFAS have been linked to health effects, which is why these chemicals are monitored and regulated.
At the time, the Kensington facility had an on-site drinking-water supply. Unitil treated that water using an activated charcoal filtration system, and testing confirmed that PFAS levels in the treated drinking water were below applicable regulated levels.
In 2020, Unitil moved the facility’s operations to Exeter, New Hampshire. The Kensington location is no longer a public water supply system.
Unitil began its current phase of environmental testing in early 2021. Phase I and Phase II Environmental Site Assessments, completed in August 2021, identified low concentrations of several substances in soil and groundwater, including:
- Arsenic – a naturally occurring element that can also be associated with certain treated materials
- Pentachlorophenol (PCP) – a chemical historically used to preserve wood
- Polychlorinated Biphenyls (PCBs) – chemicals historically used in electrical equipment
- Petroleum-Related Substances – oil and other compounds associated with petroleum products or releases from oil containing equipment
Some of these substances can affect human health or the environment if exposure occurs at sufficiently high levels. The concentrations identified in 2021 were low. Unitil reported the findings to NHDES and continued testing.
Additional testing in 2023 identified some concentrations above applicable regulatory levels. NHDES directed Unitil to conduct further investigation to better understand where these substances were coming from and how they were distributed in the area. Unitil submitted a Supplemental Site Investigation report in June 2023.
Testing conducted in 2024, 2025, and 2026 found concentrations below applicable regulatory levels.
Unitil has conducted multiple rounds of PFAS sampling at nearby residential properties. One property had a PFAS result above the applicable regulated level in 2023.
Subsequent testing conducted in 2024, 2025, and 2026 showed that the concentration decreased below the applicable regulated level.
Unitil continues to provide bottled water to that property.
Resources:
- PFAS in New Hampshire: What you need to know (NH DES Factsheet)
- NH Department of Environmental Services Remediation Webpage
Reports
- 2026 - Second SSI scope letter - Second SSI Report will be available in the spring of 2027
- 2025 - Sixth Groundwater Management Permit (GMP)
- 2023 - First Supplemental Site Investigation (SSI) Report
- 2022-23 - Third PFAS Sampling Report of Abutters
- 2021 - Phase I and II Environmental Site Assessment (ESA) Report
- 2021 Work Plan & Schedule Supplemental Site Investigation
- 2019 - First PFAS Sampling Report of Abutters
- 2019 - First Per- and Poly-fluoroalkyl Substances (PFAS) Sampling Report for on-site Public Water Supply (PWS)
- 2017 - Leaking Underground Storage Tank (LUST) Soil Remediation
- 1994-95 Three Underground Storage Tank (UST) Removal Report
Questions?
For questions about the investigation, testing, or monitoring, please contact Thomas J. Murphy, CPEA - Unitil's Environmental, Health & Safety Manager at 1-603-379-3829 or murphyt@unitil.com.
