Portsmouth Water System PFC Sampling Update: May 28, 2019
Per- and polyfluoroalkyl substances (PFAS) are a diverse group of compounds resistant to heat, water, and oil. For decades, they have been used in hundreds of industrial applications and consumer products such as carpeting, apparels, upholstery, food paper wrappings, fire-fighting foams and metal plating. In May, 2014, the City of Portsmouth was contacted by the New Hampshire Department of Environmental Services the samples from the Haven Well, part of the Pease Tradeport drinking water system, had a PFAS compound – PFOS – that exceeded the drinking water health advisory at that time. The well was immediately shut down. The Air Force’s engineering consultant has been performing frequent routine sampling of the water supply wells in the system near the Haven Well for PFAS compounds (also referred to as PFCs).
Water Supply Sampling of PFAS
The City of Portsmouth’s water supply staff continue to monitor all of our public water supply sources for Perfluorinated compounds (PFAS) every six months. Above are the most recent analysis of the Portsmouth supply sources taken in April 2019. The water samples for this round were analyzed using the detection limits proposed by the New Hampshire Department of Environmental Services (NHDS) as part of the rulemaking process to set Maximum Contaminant Levels (MCLs) for four PFAS compounds. The following information provides that detail:
- Env-Dw 712.28 Laboratory Methods, Sampling Protocols, and Method Reporting Limits for PFC Contaminants. (c) Method reporting limits for PFC contaminants shall not exceed those set forth in Table 712-2, below:
Perfluorooctanoic acid (PFOA) 2 ng/L (ppt)
Perfluoroctane sulfonic acid (PFOS) 2 ng/L (ppt)
Perfluorononanoic acid (PFNA) 2 ng/L (ppt)
Perfluorohexane sulfonic acid (PFHxS) 2 ng/L (ppt)
The following table summarizes the most recent monitoring results, in Parts-per-Trillion (ppt) for the City of Portsmouth water sources utilizing this laboratory method and reporting limits. The table also includes the MCL levels as originally proposed by the NHDES on December 31, 2018.
These results show detections of compounds that, at times, were previously reported as Non-Detect (ND) in past updates. These detections do not necessarily mean an increase in any compound from when the last time they were sampled but simply that the laboratory methods for PFAS analysis continue to evolve and improve, allowing for lower and lower detection and reporting limits. The following chart shows a comparison of how those limits have gone down for one of the compounds, PFOA, from 20 ppt to 0.23 ppt, almost 100 times less than in 2014. Detection limits for all of the other PFAS compounds sampled also have lower levels.
Many other water systems throughout New Hampshire have experienced detections testing at these lower levels. According to data provided by the NHDES these systems include those on the Seacoast; Seabrook, Aquarion Water in Hampton, North Hampton and Rye, the Rye Water District, Dover and Rochester.
An update posted on the NHDES website on February 21, 2019 noted that “New Information May Change NHDES Proposed PFAS Drinking Water Standards.” The following information was provided:
On December 31, 2018, the New Hampshire Department of Environmental Services (NHDES) initiated rulemaking to establish Maximum Contaminant Levels (MCLs) and Ambient Groundwater Quality Standards (AGQS) for four per- and polyfluoroalkyl substances (PFAS) – perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA) and perfluorohexanesulfonic acid (PFHxS).
After the initial proposal, new scientific information was evaluated by NHDES that may change the proposed drinking water standards. Specifically, a new assessment tool developed by the Minnesota Department of Health allows for a quantitative estimate of infant and child exposure to PFAS through breastmilk and/or formula. This peer-reviewed model was published at the beginning of January after NHDES filed its Initial Proposal. NHDES’s assessment of the exposure model for the interaction of drinking water levels of PFAS and breastfeeding (Goeden et al, 2019) indicates that health-based drinking water or groundwater standards for PFOA and PFOS would potentially be lowered significantly below the initial proposal figures of 38 parts per trillion (ppt) and 70 ppt, respectively. NHDES is continuing to review the suitability of this assessment tool for PFHxS and PFNA based on this and other studies released in 2019. NHDES will need to complete a review of the technical and cost implications of these health-based calculations, and any public comment received, prior to issuance of the Final Proposal.
The NHDES website is providing updates and additional information regarding upcoming public meetings about these standards. This site can be accessed at: https://www4.des.state.nh.us/nh-pfas-investigation/
Given all this information and the laboratory capabilities to detect at these lower levels, the City will now sample these water sources quarterly to assess any trend in the detected compounds and to also prepare for the pending MCLs. We have also put a formal request into the Air Force to have their consultant performing the monthly sampling of the Pease, Portsmouth and Collins wells have them analyzed using the NHDES recommended detection limits.
Additional information can be accessed at our website or by calling Al Pratt, Water Resources Manager, at: 603-520-0622 or Brian Goetz, Deputy Director of Public Works at: 603-766-1420.
Please read the full report here.
Health Advisory Levels
In May 2016, the EPA set a Lifetime Health Advisory Level of 70 ppt for PFOS and PFOA. According to EPA information these health advisory levels were calculated to offer a margin of protection for all Americans throughout their life from adverse health effects resulting from exposure to these contaminants in drinking water. In order to assure compliance with the newly adopted health standard, the City of Portsmouth’s water division adopted a policy of monitoring PFAS in all of our water sources twice a year. The Air Force will continue with monthly sampling of the Portsmouth, Collins, Harrison and Smith wells.
The State of New Hampshire is currently reviewing Health Risk Assessment information to recommend Maximum Contaminant Levels (MCLs) for PFOA, PFOS, PFHxS and PFNA. We anticipate the release of that recommendation in the very near future. That recommendation will be utilized by the state to start the rulemaking in January 2019 to set the final standards.