The Guam Waterworks Authority is currently analyzing the impact of newly released lifetime drinking water health advisory for per- and polyfluoroalkyl substances (PFAS) on utility production and treatment operations, and is also developing a protocol to address the change in advisory for review with the Guam Environmental Protection Agency, according to GWA Executive Director Miguel Bordallo.
PFAS are a group of emerging contaminants known as “eternal” chemicals because their components break down very slowly over a long period of time. PFAS can accumulate in the body and are linked to adverse health effects.
“However, research is still ongoing to determine how different levels of exposure to different PFAS can lead to various health effects. Research is also ongoing to better understand the health effects associated with low levels of exposure. to PFAS over long periods of time, especially in children,” the U.S. Environmental Protection Agency StateD.
In 2016, the EPA Position Health advisory levels for two types of PFAS – perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) – at 70 parts per trillion, individually or combined.
PFOS was detected at five sampling sites in Guam. Three of these sites gave concentrations higher than the health advice at the time. The wells concerned in use were closed and then equipped with filtration systems.
Recent health effects studies show that PFOA and PFOS can impact human health at exposure levels far below those listed in the 2016 advisory, according to the USEPA.
The 2022 interim health advisory now sets the level of PFOA at 0.004 parts per trillion and PFOS at 0.02 ppt. The US EPA has also issued final health advisories for two other PFAS: perfluorobutane sulfonic acid and its potassium salt (PFBS), and hexafluoropropylene oxide dimer acid (HFPO) and its ammonium salt ( GenX chemicals). The first is set at 2,000 ppt and the second at 10 ppt.
GWA Water Quality 2021 report shows PFAS levels in groundwater ranging from undetectable levels at test limits down to 0.05 parts per billion, or 50 parts per trillion.
The Guam Daily Post has asked to know the concentration levels among all water wells in Guam and whether they exceed the interim advisory. GWA didn’t provide specific numbers, but Bordallo said the utility was working to do more rigorous sampling and analysis.
“A significant amount of sampling and analysis (beyond what was required under previous LHALs) is required and GWA is working to complete this as quickly as possible to support the development of appropriate and grounded plans. on data for the short term. We note that the US EPA plans to conduct a nationwide awareness campaign in October/November on PFAS, and that to date they have not issued any regulations for PFAS compounds,” Bordallo said.
Health advisories are not enforceable. It is non-regulatory, non-enforceable information “to assist federal, state, tribal, and local authorities and managers of public or community drinking water systems in protecting public health in the event of a spill or contamination”, said the USEPA.
However, the federal agency is developing a proposed national primary drinking water rule for PFOA and PFOS, with a proposed rule expected in fall 2022 and a final rule in fall 2023. Interim provisions will remain in place until the USEPA establishes the National Primary Drinking Water Regulation, the agency said.
“In the meantime, all previously identified wells requiring treatment remain in service using filtration (granular activated carbon), and planned construction of additional treatment systems continues with the necessary funding already in place. GWA is assessing in ongoing PFAS treatment technologies and has already initiated planning for additional treatment technologies that may be warranted with new LHALs.Information on these treatment technologies is shared with our partners (DoD) through the One-Guam Water initiative,” Bordallo said.
“In addition to working with Guam EPA and other government agencies on ongoing actions to address known sources of PFAS contamination, GWA provided information on potential sources of PFAS contamination to Guam EPA and USEPA for their action in the fight against their elimination/remediation,” he added.
PFAS can be found in fire-fighting foam, known as aqueous film-forming foam, or AFFF, previously used in Guam for emergencies and training activities, said a 2018 release from Joint Region Marianas.
It can also be found in many commercial household products, including stain and water repellent fabrics, release agents, varnishes, waxes, paints and cleaners, the statement added.
US Air Force and US Navy bases in Guam have tested PFAS in their water supplies.
Concentrations reported of the Andersen Air Force Base drinking water quality report showed PFOS was detected at 1.4 ppt and 1.3 ppt, lower than the 2016 advisory levels, but significantly higher than the levels listed in the current draft advisory.
Guam Naval Base Water report showed three sinks exceeding even the 2016 advisory, with the NRMC-2 sink recorded in September 2021 at a whopping 1,804 ppt for PFOA and PFOS combined, the vast majority being PFOS. All wells would exceed the draft advisory with one or both substances.
“Per DoD policy, alternate water is provided until potable water is tested and is consistently below (health advisory level). PFAS levels at wells NRMC-1 and NRMC- 2 remain high and both wells remain offline and not in use,” the report said.