PFAS Sampling Summary: Most Recent Samples
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). Prior to the installation of activated carbon filters for the Smith and Harrison Wells (Pease Wells), the Smith Well was sampled weekly and the Harrison Well was sampled every two weeks while the Portsmouth and Collins wells were sampled monthly. In addition to the water supply wells, the Air Force’s consultant samples other monitoring wells in the surrounding area to track any potential migration of PFAS to the aquifer that may be moving toward the supply wells. To date, PFAS levels have remained consistent and all detected levels of PFOS and PFOA in the currently operating supply wells remain below the EPA’s current health advisory standard of 70 parts per trillion. The newly-installed activated carbon treatment system for the Harrison and Smith wells is also sampled, utilizing the same laboratory as the Air Force’s consultant uses to provide consistency. Data provided by the Air Force is updated on the City’s website once it has been validated by the laboratory and provided to the City by the Air Force’s consultant. The data from the carbon treatment system will be updated periodically.
All of the Portsmouth water sources were sampled for PFAS in May 2014 by the New Hampshire Department of Environmental Services (NHDES). Samples were also taken in two locations of the City’s water distribution system (one at the DPW on Peverly Hill Road and another at the meter pit in New Castle). All of the Portsmouth water sources were also sampled as part of the USEPA’s third Unregulated Contaminant Monitoring Rule (UCMR 3). Four rounds of UCMR3 sampling were performed between July 2014 and April 2015. Those sample results were below the laboratory’s reporting limit for all PFAS.
In June 2016 the NHDES sent out a request to all community and other non-transient water systems to voluntarily collect a water sample for PFOA and PFOS and share the results with NHDES. They also recommended that a lab certified or accredited to complete EPA Method 537 with detection limits of at least 5 nanograms per liter (parts-per-trillion or ppt) be utilized. Following this request Portsmouth water operations staff sampled for PFAS. A second round of sampling was performed in November. The lower reporting limit revealed that the Greenland well results had an average level of 9 ppt of PFOS. It should be noted that the levels were also flagged by the laboratory as “J” values, which means that they were an estimate.
As previously mentioned, the Portsmouth and Collins wells are sampled monthly by the Air Force as part of the Pease PFAS water quality monitoring program. Though there are detections, they are generally less than what we see in the Harrison and Smith wells. To date, the Air Force’s consultant’s analysis of this data show no increasing trend in PFAS concentrations. If concentrations show an increasing trend, or if the regulations get revised, then treatment of these wells may be considered.
It should be noted that both the Air Force’s engineering consultant and the City of Portsmouth are sampling for more PFAS parameters than most other water systems. The Unregulated Contaminant Monitoring that took place across the country in 2014 and 2015 (which the City’s water system participated in) only required sampling for six parameters – PFOS, PFOA, PFBS,PFHxS, PFHpA, and PFNA. When the Haven Well contamination was discovered in 2014, DES recommended that the Air Force sample for more compounds than the UCMR required. It was also recommended that a lab capable of sampling at lower levels be utilized. At the time, there were only two labs that could do this type of analysis, Maxxam was one of them and they were selected and have been used for sampling ever since. The DES has been very proactive with this issue and they put out a recommendation and request to all public drinking water systems that they re-sample their water sources utilizing methods that detect PFAS compounds more precise laboratory method than when many drinking water systems in the U.S. sampled for PFAS compounds in 2014-2015. Water systems that had no detections utilizing the UCMR methods at that time now have detections - Dover, Rye, Hampton (Aquarion), Portsmouth and many other water systems in New Hampshire. Detailed information on this sampling can be accessed at the DES website:
As for the tap sampling, we have on occasion sampled for PFAS at the tap. Samples were taken last year in June at two of our DES sample sites, one on Sagamore Road and the other at the Portsmouth Library using the same sample method and laboratory (Maxxam) as the Air Force’s consultant uses (to be consistent). Results for PFOA and PFOS were non-detect. Five other compounds were detected at low levels in the tap samples collected in 2016: PFBS, PFHpS, PFPeA, PFTeDA, and PFTrDA. The level of these compounds at the taps were equivalent to the sources that served the sample location, with the exception of PFHpS which was not detected at any of the sources, thus likely associated with the facility plumbing or a laboratory analysis issue. The results of these compounds were all estimated by the lab and are near the limits of the lab's ability to detect. We do not intend to continue twice a year sampling at the tap locations based on the confirmation last year in the field. We will continue twice a year sampling of PFAS at all of our source waters. A copy of all the sample results is included on the City’s website and will be updated periodically.
The NHDES has stated that because of the widespread use of PFAS it is not unusual to find these compounds in groundwater and surface water throughout the nation anywhere samples are analyzed at the part per trillion level. The recent voluntary sampling of public water systems in New Hampshire shows detected PFAS in multiple drinking water systems, including those that previously had no detections utilizing the UCMR3 methods. The NHDES also notes that concentrations of PFAS in groundwater below 10 parts per trillion are normal and can be considered anthropogenic “background” concentration. Additional information on New Hampshire public drinking water sampling for PFAS can be accessed at the NHDES website: http://des.nh.gov/organization/commissioner/pfoa.htm
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 will continue to monitor for PFAS in all water sources twice a year. The Air Force will continue with monthly sampling of the Portsmouth, Collins, Harrison and Smith wells.