Which Fluorinated Compounds in This Record Now Carry a 2024 Federal MCL?
The EPA's recent Unregulated Contaminant Monitoring Rule (UCMR5) survey of the Dover Water Department’s system shows no detections above reporting levels for key per- and polyfluoroalkyl substances (PFAS) from March 2024 through May 2025. Among the 10 monitored compounds, including PFOA, PFOS, PFHxS, PFNA, and others, all results were below the federal maximum contaminant levels (MCL) effective in 2024. For example, PFOA and PFOS both have federal MCLs set at 4.0 nanograms per liter (ng/L), or parts per trillion (ppt), and no samples from the Dover system exceeded these thresholds. Some PFAS compounds do not yet have a federal MCL, reflecting ongoing review and evaluation.
Why a Granular Carbon Bed and an Ion-Exchange Resin Are Documented Differently for PFAS
Two main treatment media are recognized for addressing PFAS in water: granular activated carbon (GAC) and ion-exchange resins. GAC works by adsorbing molecules like PFOA and PFOS onto its surface, often effective for a broad range of PFAS compounds, especially longer-chain types. Ion-exchange resins are designed to selectively capture specific PFAS molecules based on their ionic charge, sometimes providing enhanced removal of shorter-chain compounds that are less adsorptive to carbon. The documented Fleck PFAS Forever Chemicals Filter employs a combination of these technologies, optimized for residential water treatment. This distinction matters because some filters may target a narrower range of PFAS, whereas others are engineered for broader effectiveness against the diverse 'forever chemicals' monitored in the Dover system.
The Hazard Index for Mixtures of Newer Compounds, Explained Without a Health Claim
PFAS substances often occur as mixtures rather than individually. Regulatory and scientific assessments sometimes use a hazard index approach that sums relative concentrations of several PFAS based on their potential to contribute collectively to health concerns. While the Dover Water Department monitored several newer PFAS compounds, none were detected above reporting levels, resulting in an effectively very low hazard index for the public water system as a whole. It's important to note that this index is a risk assessment tool and does not imply immediate health effects. Instead, it helps guide regulatory focus and treatment priorities.
What the Measured Range Means Against the Relevant Federal Standard, and What It Does Not Mean
The absence of detections above reporting levels in the Dover system means the sampled water met or was below the minimum quantification limits set for the survey, which are well below the federal MCLs established for public water safety. These results apply to the public water system serving approximately 39,491 residents through 13,408 connections. However, they do not provide specific information about any individual household's tap water, which can vary due to plumbing materials, home treatment devices, or private well conditions. To understand PFAS presence in your individual water, a specialized laboratory test of your tap water would be necessary.
Why Aesthetic Secondary Standards Differ From Health-Based Limits, Applied to This Constituent
PFAS do not have secondary aesthetic standards like taste or odor thresholds commonly set for other contaminants. This difference highlights that federal MCLs for PFAS are determined based on potential health effects rather than aesthetic considerations. For water systems like Dover’s groundwater supply, addressing PFAS focuses on compliance with these health-based guidelines rather than cosmetic water quality parameters.
In summary, the Dover Water Department's 2024–2025 federal monitoring found no detectable PFAS compounds above reporting levels or federal MCLs. This data covers the public water system, not individual household samples. The Fleck PFAS Forever Chemicals Filter offers a documented residential option using advanced carbon and ion-exchange technologies to reduce a broad spectrum of fluorinated compounds often called "forever chemicals." Government monitoring data and federal standards are accessible through the EPA’s Safe Drinking Water Information System and UCMR databases.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2025-05-01. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR5 monitoring (2023-2025) for DOVER WATER DEPARTMENT (DE0000571), DE: 320 results across 10 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level