This week, you need to decide how to interpret federal water sampling results about PFAS within your public water system and whether to consider additional treatment options at home.
Interpreting Median and Range Values from System Sampling
The EPA's recent monitoring for the Mashantucket Pequot Water System in area 01 shows that several PFAS compounds have been detected at low levels in the public water supply. For example, PFOA was found in 3 of 4 samples, with a median detected concentration of 0.0071 micrograms per liter (µg/L) and a highest reading of 0.0074 µg/L. Other PFAS such as PFOS, PFHxS, and PFNA were not detected above reporting levels. Several shorter-chain PFAS like PFPeA and PFHxA were consistently detected but at very low values. These figures represent what the water system tested at the system level, not your household’s specific water quality. Only a test of your home’s water can determine your own exposure levels.
What Happens To Water After Effective Filtration at Your Tap
When water from the Mashantucket Pequot system passes through a filtration device like the C-Series PFAS Forever Chemicals Filter, compounds such as PFOA and other PFAS are reduced at the point of use. This filtration technology is designed to target and capture a wide range of these persistent chemicals, thereby improving water quality at the tap. This means water used for drinking and cooking can have significantly lower PFAS concentrations compared to unfiltered supply water. The filter ships ready to configure for household use.
Understanding Terms: Detected, Median, and Range in Water Data
The terms in EPA sampling reports require careful interpretation. A compound recorded as 'detected' means instruments measured it above a laboratory reporting level, but this does not imply a violation or health risk. The 'median' is the middle value of detected concentrations across samples, and the 'range' shows the lowest to highest detections recorded. These statistics describe the public system's water at sampled points and times but do not reflect specific tap water conditions in any home.
Which Household Uses Are Most Impacted by PFAS Presence
PFAS in water primarily affect uses involving ingestion — drinking, cooking, and preparing beverages — since these chemicals can accumulate in the body. Appliances that heat water or use it directly for consumption, such as coffee makers or ice machines, can also reflect PFAS presence if filtering is not in place. Reducing PFAS at the point of use helps ensure that water for these purposes contains fewer of these persistent substances.
How PFAS Contaminants Enter Groundwater and Distribution in This Area
PFAS compounds can enter groundwater or public water systems through industrial releases, runoff from areas where firefighting foams have been used, or leaching from contaminated sites. In the Mashantucket Pequot system, periodic federal monitoring indicates low-level occurrences of several PFAS types, reflecting regional environmental factors and water source characteristics as documented by EPA sampling.
What the Range of PFAS Levels Means Against Federal Guidelines and What It Does Not Mean
Federal Maximum Contaminant Levels (MCLs) for certain PFAS, like PFOA and PFOS, will be enforced beginning in 2024 at levels such as 4.0 nanograms per liter (ng/L). Sampling in this system showed PFOA slightly above the reporting level but well below the MCL threshold, while PFOS was not detected above the reporting level. This indicates compliance with current health-based standards. However, detections alone do not signal unsafe water, and aesthetic or secondary standards are not health-based and must not be confused with safety limits.
What You Should NOT Conclude From Regional Data About Your Home’s Water
Data from the Mashantucket Pequot Water System provides valuable context but does not specify your household's water quality. Detection of PFAS in the system does not mean your tap's water exceeds health standards nor that the water is unsafe. To know your home's water quality confidently, you would need to conduct specific water testing at your tap. If concerned, using a C-Series PFAS Forever Chemicals Filter can reduce PFAS presence at the point of use, improving the water you drink and cook with.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2024-05-13. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR5 monitoring (2023-2025) for Mashantucket Pequot Water System (010106001), 01: 40 results across 10 listed contaminants, 19 detections above the reporting level; 3 results above a 2024 federal MCL