In 2017, NHDES requested assistance from the U.S. EPA’s Office of Research and Development (EPA ORD) to conduct analyses of various samples for the potential existence of PFAS compounds. On January 30, 2020 EPA ORD issued Reports #7 and #8 in a series of work products that document results of the analyses performed on the various samples. Reports #7 and #8 convey the results of non-targeted PFAS analyses for surface water and groundwater samples that NHDES staff collected in 2017 and 2018.
A total of 20 groundwater samples (including three duplicate samples) were collected and submitted to EPA ORD (Figure 1). Groundwater sources sampled for this study included monitoring wells and private wells no longer used for drinking. Wells were selected for inclusion in this study based on results of prior PFAS analyses so that a range of PFAS concentrations could be evaluated, including highly contaminated monitoring wells close to the Saint-Gobain Facility.
Surface water samples (including one duplicate sample) were collected from five different locations and submitted to EPA ORD (Figure 1). Samples were collected from the Merrimack River (EPAORD 002 and EPAORD 003) and Dumpling Brook (EPAORD 001, EPAORD 003, and duplicate sample EPAORD 004). Discharge from the stormwater system that drains the Saint-Gobain Facility was sampled at the Outfall (EPAORD 006) during dry conditions when the water discharging from the system may be related to groundwater infiltration. EPA ORD detected and tentatively identified 24 different PFAS in surface water and stormwater (Report #7). Twelve PFAS were tentatively identified in three monitoring wells located near the Saint-Gobain Facility. The results presented in these two reports (described in terms of peak count area) are considered semi-quantitative because known standards for each compound were not used to calibrate the peak count area to a mass concentration in each sample.
NHDES is analyzing the results presented in these two EPA ORD reports in the context of the Southern New Hampshire PFAS Investigation.