If you suspect firefighting foam, textile finishing, or landfills are a source of PFAS contamination locally
In GU, the public water system, designated GWA CENTRAL WATER SYSTEM, reports no detections above reporting levels for various PFAS compounds, including PFOA, PFOS, PFHxS, PFNA, HFPO-DA, PFBS, PFHxA, PFPeA, PFBA, and PFHpA. These compounds often originate from sources such as firefighting foam, textile finishing industries, and landfill leachate. The absence of detectable PFAS above reporting levels suggests these sources have not impacted the public water supply at measurable levels during the EPA’s 2023-2025 monitoring period.
If you want to understand how the UCMR5 monitoring differs from earlier surveys like UCMR3
The UCMR5 monitoring campaign, conducted between February and December 2025 by the EPA, focuses on a broader group of PFAS compounds than UCMR3, with enhanced sensitivity reflected in lower reporting limits, measured in the range of parts per trillion (nanograms per litre). Unlike UCMR3, which targeted fewer compounds predominantly PFOA and PFOS, UCMR5 includes newer fluorinated compounds such as HFPO-DA and a range of other per- and polyfluoroalkyl substances. This expanded scope helps capture a more comprehensive picture of 'forever chemicals' in public water systems without indicating health-based violations.
If you want to distinguish what these public water records mean compared to private well testing
Public water system records like those for GWA CENTRAL WATER SYSTEM provide area-wide sampling data under federal regulations, establishing occurrence trends but not individual well conditions. This system serves many households, so the absence of PFAS detections above reporting levels reflects the overall system status, not a guarantee for any single residence’s water. For private wells, only specific testing of the well water can determine the presence and concentration of PFAS compounds, as small-scale factors can vary significantly.
If you wonder why PFOA and PFOS concentrations are given in nanograms per litre with four decimal places
PFAS compounds such as PFOA and PFOS are measured at extremely low concentrations, typically in nanograms per litre (ng/L), which is equivalent to parts per trillion (ppt). Reporting at four decimal places, such as 0.004 µg/L, indicates the limit of detection sensitivity, allowing measurements to capture even trace amounts of these substances. This precision helps regulatory agencies track and manage PFAS occurrences proactively, even when levels remain far below federal maximum contaminant levels (MCLs) set for health protection.
If you want to prepare before seeking advice about PFAS water treatment options
Before considering water treatment solutions, note the specifics of your water source, such as whether you receive public water or rely on a private well. Keep records of any recent testing results for PFAS compounds if available. Understand that the local public water system in GU currently shows no PFAS detections above reporting levels, so individual testing is essential to confirm your household’s water quality. Knowing which PFAS compounds are of concern and their concentrations will help in selecting an appropriate water treatment system.
For households seeking targeted removal of PFAS, the C-Series PFAS Forever Chemicals Filter is designed to address a broad range of per- and polyfluoroalkyl substances. This system ships ready to configure, enabling users to reduce the presence of 'forever chemicals' in their water supply effectively.
In summary, the GU public water system record from EPA monitoring reveals no detectable PFAS above reporting levels, reflecting a low occurrence in this region’s municipal supply. However, individual water quality can vary; testing your own well or home water is the only way to know its specific PFAS levels and decide if filtration is advisable.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2025-12-11. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR5 monitoring (2023-2025) for GWA CENTRAL WATER SYSTEM (GU0000003), GU: 80 results across 10 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level