Tap water flowing to parts of Cabarrus County, North Carolina, contains per- and polyfluoroalkyl substances, commonly called PFAS or “forever chemicals,” at concentrations that meet or exceed the federal maximum contaminant level. The contamination traces back to water sourced from Concord’s Hillgrove Water Treatment Plant, which feeds into the supply serving the Town of Harrisburg and surrounding communities. With enforceable federal limits now on the books and compliance deadlines approaching, the findings put local utilities under pressure to act before regulators step in.
What Testing Revealed at the Hillgrove Plant
The Town of Harrisburg disclosed that PFAS levels in water sourced from Concord’s Hillgrove Water Treatment Plant are at or above the federal Maximum Contaminant Level. The town draws from a complex network of 10 intakes spanning wells, Charlotte’s water system, and Concord’s supply, meaning that not every tap in the service area carries the same concentration at any given time. That blended sourcing arrangement is central to Harrisburg’s position that it has no current violations, because compliance under the EPA’s PFAS rule hinges on running annual averages rather than single-sample readings.
But the blending math cuts both ways. If the Hillgrove intake consistently delivers water at or above the limit, households that happen to receive a higher proportion of Concord-sourced water on a given day could face exposure spikes that the annual average obscures. Targeted, intake-level sampling would clarify whether certain neighborhoods bear a disproportionate share of the risk. Without that granularity, the running-average framework may offer statistical comfort while leaving real gaps in public health protection.
Federal Limits and What They Mean for Residents
The EPA’s final PFAS National Primary Drinking Water Regulation sets enforceable maximum contaminant levels of 4 parts per trillion for PFOA and PFOS, two of the most studied forever chemicals. Three additional compounds, PFHxS, PFNA, and GenX (also known as HFPO-DA), carry a limit of 10 parts per trillion each. The rule also introduces a Hazard Index for mixtures of these substances, recognizing that combined exposure to multiple PFAS compounds can pose health risks even when individual chemicals fall below their standalone caps.
For a family in Harrisburg, these numbers translate into a straightforward question: is the water safe to drink today, or only safe on paper once averaged across a year? Because compliance is calculated on running annual averages, a system can record individual samples above 4 ppt for PFOA or PFOS and still avoid a formal violation as long as the yearly math stays below the line. The EPA recently confirmed it will keep the maximum contaminant levels for PFOA and PFOS unchanged, though the agency is proposing adjustments to compliance timelines and exemptions for other regulated PFAS. That means the 4 ppt threshold is not going away, and utilities that have been waiting for a regulatory softening will need to invest in treatment or alternative sourcing.
North Carolina’s Broader PFAS Monitoring Picture
Cabarrus County’s situation sits within a statewide pattern. The North Carolina Department of Environmental Quality has conducted PFAS sampling of public water systems across the state, selecting systems for follow-up testing based on earlier detections. Data tables covering municipal and county systems from 2022 and small systems from 2023 and 2024 show that PFAS contamination is not confined to the well-known GenX crisis along the Cape Fear River. Smaller community water systems in and near Cabarrus County have also recorded detectable levels of PFOS, PFOA, GenX, PFBS, PFNA, and PFHxS, according to the 2023 small-system sampling data table, which reports results in nanograms per liter by system name, county, sample date, and source water type.
At the federal level, the EPA’s Fifth Unregulated Contaminant Monitoring Rule program has been collecting PFAS occurrence data from water systems nationwide between 2023 and 2025. The UCMR 5 Data Finder, most recently refreshed as of January 15, 2026, allows users to search by public water system name or ID and compare EPA-calculated averages against the new maximum contaminant levels. Together, the state and federal datasets create a layered evidence base that confirms PFAS detections are not isolated incidents but a recurring feature of water systems drawing from surface sources in the Charlotte-Concord metropolitan corridor.
Why Blended Sourcing May Not Be Enough
Harrisburg’s 10-intake blending strategy is designed to dilute contaminants from any single source, and the town has stated that it currently has no violations. That framing is technically accurate under the running-annual-average compliance structure. Yet the approach assumes that dilution is a permanent fix rather than a temporary buffer. If PFAS concentrations at the Hillgrove plant rise, or if other intakes develop their own contamination issues, the blending margin shrinks. Utilities across the country facing similar situations have increasingly turned to granular activated carbon filtration, ion exchange systems, or high-pressure membrane treatment to strip PFAS at the plant level rather than relying on dilution alone.
The absence of publicly documented enforcement actions specific to Cabarrus County systems does not mean regulators are powerless. Residents who believe their water system is not adequately addressing PFAS can submit concerns through the EPA’s online portal for environmental violations, which routes complaints to appropriate federal or state agencies. In practice, however, enforcement often lags behind scientific findings and community worries, particularly when systems remain technically compliant on paper. That gap between regulatory thresholds and lived experience is where local pressure, public meetings, and transparent data-sharing can push utilities to move faster than the minimum required pace.
What Residents Can Do While Utilities Catch Up
For households in Harrisburg and neighboring communities, navigating PFAS concerns starts with information. Residents can review the town’s notices about Hillgrove-sourced water and compare them with statewide PFAS sampling summaries and federal monitoring data. By checking system-specific entries in the state sampling tables and searching their utility in the national monitoring database, customers can see how often PFAS has been detected, which compounds are present, and how close those levels come to the federal thresholds. That context helps families decide whether interim measures, such as point-of-use filters certified for PFAS reduction or relying on alternative water sources for infants and pregnant people, are warranted while longer-term treatment projects are planned.
Community engagement also shapes how quickly utilities move from acknowledgment to action. Public comment periods on local budgets, infrastructure plans, and state-level drinking water programs give residents a chance to ask whether PFAS treatment is being prioritized alongside other capital needs. When neighbors share information about sampling results and regulatory changes, it becomes harder for contamination concerns to remain an abstract, technical issue. Instead, PFAS becomes part of a broader conversation about how Cabarrus County and the Town of Harrisburg will balance growth, industrial activity, and the right to safe drinking water in the years ahead.
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*This article was researched with the help of AI, with human editors creating the final content.
