Understanding What Area Data Shows and Does Not Show
EPA monitoring reflects large public system averages, not individual home water
The AQUA PA MAIN SYSTEM serves more than 820,000 residents in Montgomery County with surface water. EPA’s Unregulated Contaminant Monitoring Rule (UCMR5) tests multiple PFAS compounds in this system but these results represent collective samples, not a specific home’s water quality. Individual testing is needed to determine household exposure accurately.
Detection above reporting levels is measurement, not a violation or safety finding
Many PFAS compounds were detected at concentrations above their reporting levels. A detection means the measured concentration exceeded the minimum level the EPA's equipment can reliably report. This is not a violation, nor does it alone indicate unsafe water.
Why a Granular Carbon Bed and an Ion-Exchange Resin Are Documented Differently for PFAS
Granular activated carbon (GAC) targets a broad range of PFAS effectively
GAC filtration adsorbs many PFAS molecules, especially longer-chain compounds like PFOA and PFOS. This method reduces their concentration by trapping them in the media.
Ion-exchange resins excel at removing shorter-chain PFAS
Some shorter-chain 'forever chemicals', such as PFBA or PFBS, are less effectively removed by carbon but can be captured selectively by ion-exchange resins that attract these charged molecules.
Which of the Fluorinated Compounds Carry a 2024 Federal MCL and Which Do Not
PFOA and PFOS have a federal maximum contaminant level of 4.0 ng/L (parts per trillion)
In Montgomery County’s system, PFOA was detected up to 12.6 ng/L and PFOS up to 9.2 ng/L, both above this new EPA MCL. These compounds are commonly studied due to their persistence and potential health impact.
PFHxS and PFNA also have 2024 federal MCLs but were mostly below their limits
PFHxS and PFNA were detected but generally under the respective federal MCLs of 10 ng/L in this system. Monitoring continues to assess their distribution.
Other fluorinated compounds detected are not yet regulated with federal MCLs
Compounds such as PFHxA, PFPeA, PFBA, and PFHpA were found in varying concentrations but currently have no federal MCL established.
How the Treated Water Differs at the Tap Once the Documented Technology Is in Place
The C-Series PFAS Forever Chemicals Filter reduces a broad spectrum of PFAS levels
This filtration technology combines granular carbon with ion-exchange resin elements designed to lower concentrations of both long and short-chain PFAS compounds effectively, improving water quality at the tap for residential users.
Filtered water typically shows lower nanograms per litre values for regulated PFAS
Use of this system can bring detected levels well below the EPA’s established MCLs for PFOA and PFOS, addressing compounds found above these limits in Montgomery County’s public water samples.
How the UCMR5 Survey Differs from UCMR3 in Compounds Tested and Reporting Levels
UCMR5 covers more PFAS compounds with lower reporting thresholds
The latest UCMR5 survey (2023-2025) examines a broader range of PFAS compounds, including newly recognized chemicals like HFPO-DA, with more sensitive detection limits than the previous UCMR3 survey.
This allows earlier identification of emerging fluorinated substances in water systems
Expanded monitoring helps track “forever chemicals” that could pose future concerns, supporting comprehensive water quality assessment in areas like Montgomery County.
How Public-System Records Differ from Private-Well Testing in What They Establish
Public system data represents aggregated results for many customers
The AQUA PA MAIN SYSTEM data reflects multiple source samples combined over time, serving hundreds of thousands of people. It offers a broad picture of regional PFAS occurrence but not household-specific conditions.
Private well testing provides specific results for an individual supply
Homeowners with private wells should conduct their own water tests to know their actual PFAS levels, since private sources vary widely and may not match public water system profiles.
Conclusion: What Montgomery County Data Does Not Confirm About Your Household Water
While the EPA’s monitoring reveals that PFAS are present in the public water system serving Montgomery County—including some compounds above new federal guidelines—this data does not specify your home's individual water quality or safety status. Only a certified laboratory test of your household water can provide that information. For managing PFAS concerns in residential water, technologies such as the C-Series PFAS Forever Chemicals Filter, which ships ready to configure, are documented solutions that address both common and emerging PFAS compounds found in this region.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2024-12-11. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR5 monitoring (2023-2025) for AQUA PA MAIN SYSTEM (PA1460073), PA: 500 results across 10 listed contaminants, 225 detections above the reporting level; 51 results above a 2024 federal MCL