The U.S. Navy responded last week to a series of questions sent in July by this news organization, ahead of a report detailing ongoing potential hazards from firefighting chemical contamination near Bucks and Montgomery County military bases.
Local communities along the county border have struggled with high levels of per- and polyfluoroalkyl substances (PFAS) in drinking water, after nationally high amounts of the unregulated chemicals shuttered hundreds of drinking water wells over the past five years. The crisis has required tens of millions of dollars to address, with the military agreeing to pay for some water filtration in Warminster, Horsham and Warrington, but left the towns and state paying additional millions to filter the chemicals from their supplies completely.
The July report revealed how the military’s local response could still be allowing some potential PFAS exposures, beyond drinking water, to slip through the cracks. In one example, the report detailed U.S. Navy documents that showed environmental officials had initially considered potential exposure to PFAS through the consumption of fish caught from polluted area waterways, but later removed the potential pathway from a planning document and declined to ask state regulators to study the issue for fear of setting “precedent.”
In an email sent Sept. 12, Lt. Brittany Stephens, a Navy spokeswoman, responded by saying that the federal Environmental Protection Agency is working on, but has not yet approved, any methods for “extraction, cleanup, and analysis of PFAS in fish tissue.”
As previously reported, other states including New Jersey have already developed processes to test for PFAS in fish tissue and established consumption advisories. After testing water bodies across the state, the New Jersey Department of Environmental Protection last year recommended limiting the consumption of large mouth bass to just once a year in waterways with PFAS levels similar to those in Bucks and Montgomery counties.
But Stephens wrote any “collection and analysis” of fish tissue without EPA methods “could carry a high degree of uncertainty or affect the reproducibility of results.”
Stephens added that both the EPA and Pennsylvania DEP had approved the Navy’s initial environmental investigation plans for the former Naval Air Station-Joint Reserve Base Willow Grove. Those plans did not include an effort to evaluate potential exposure to PFAS through fish consumption.
The July report also noted that in addition to fish consumption, early drafts of an exposure model developed at Willow Grove removed other potential routes of exposure to current residents, including “incidental” ingestion of sediment or surface water from area creeks and streams.
Stephens said the document is a “living/evolving” model that is updated as the Navy’s investigation progresses.
“The Navy identified that there was insufficient data to describe certain off-site exposure pathways to current/future residents… resulting in the revision,” Stephens said. “To address this data gap, the Navy expanded off-site sampling to include quarterly sampling of surface water and sediment to determine exposure.”
Stephens said that data will help the Navy and regulators to refine the exposure model in the future.
The July report also detailed emails from some Navy environmental personnel, in which they suggested consideration of other potential routes of exposure beyond drinking water as the department formulated a PFAS strategy. That included considering the potential for PFAS contamination near facilities that process waste, other disposal locations, or along routes of migration from bases.
Asked about the comments, Stephens said the EPA has only developed a lifetime health advisory (LHA) for drinking water for two kinds of PFAS, but said the Navy is still considering other routes.
“This LHA does not apply to other media or routes of exposure,” Stephens said. “However, in the absence of any other EPA guidance or directive, the Navy has proactively established sampling initiatives at every installation using the LHA as an indicator of PFAS impacts, sampling not only drinking water but also groundwater and sediments.”
As the EPA develops methods for other routes, the Navy will incorporate them, Stephens added.
Additional issues identified in Department of Defense documents were the ability of some “smaller” PFAS to slip through conventional filters, and also potentially survive incineration when PFAS-laden material is burned. Stephens was also asked where treatment sludges and filters that could have contained PFAS were disposed of.
Stephens said the Willow Grove facility operated a waste water treatment plant until it was demolished in 2011 and 2012.
“There are limited records regarding filtration media or sludge disposal, but the Navy is currently performing a comprehensive PFAS investigation to include any suspected locations potentially impacted by PFAS,” Stephens wrote.
Stephens said there are no records of a similar plant existing at the former Naval Air Warfare Center Warminster.
Regarding incineration, Stephens said the Navy as a whole has incinerated 46,405 pounds of firefighting foam containing perfluorooctane sulfonate (PFOS), a primary PFAS used in foams, to date. However, Stephens wrote, “The Navy has not used incineration of PFAS-laden material for the cleanup efforts” at Willow Grove or Warminster. It was unclear whether that included foams, or referred to other materials such as contaminated soils.
Asked about the potential for some PFAS to slip through filters, Stephens said the EPA had approved granular activated carbon (GAC) as a “100% effective” treatment media for PFOS and perfluoroctanoic acid (PFOA).
“Toxicity and risks associated with shorter chain PFAS have not been established and remain unknown,” Stephens wrote.
Local towns impacted by PFAS use dual carbon filters at each impacted well, meaning they have extra protection and time to swap units out after the chemicals begin to “break through” the first unit. Local municipal officials say data show the process prevents all PFAS chemicals from entering drinking water.
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