Government sampling of the Statesville public water system, managed by Iredell Water Corporation, shows chromium-6 (hexavalent chromium, Cr(VI)) detected in over half of the tested samples. Concentrations varied, with a highest detected level of 4.9 micrograms per liter (µg/L or parts per billion), well below the 100 µg/L maximum contaminant level for total chromium. This data reflects the overall system and not any single home’s water profile.
How Chromium-6 Levels May Shift From Source to Tap
Chromium-6 commonly exists as a dissolved ion in surface water sources like those serving Iredell Water Corporation. Its oxidation state can change as water moves through treatment steps, storage, and distribution pipes. For example, chromium-6 can convert to chromium-3 in certain conditions, which is less mobile and less toxic. Conversely, some household plumbing materials or chemical interactions may alter chromium's form before it reaches your tap. Testing at your own tap is necessary to determine your household’s specific chromium-6 level.
Understanding the UCMR3 Survey Purpose and Household Relevance
The Unregulated Contaminant Monitoring Rule 3 (UCMR3) was designed to detect emerging contaminants like chromium-6 across public water systems nationwide. Sampling in Iredell County occurred from 2013 to 2015, yielding data to inform future regulation and research. However, this survey does not assess compliance or safety for individual homes but provides a snapshot of system-wide water quality over time. Your household water may differ due to local plumbing, water use patterns, or treatment devices.
Long-Term Outcomes of Untreated Chromium-6 in Household Water
Chromium-6 in drinking water, when present at low levels like those measured in this system, is not federally regulated by an MCL. Without treatment, chromium-6 may persist through household water lines. Long-term ingestion at higher exposures has drawn scientific study, but the concentrations detected here remain far below total chromium regulatory limits. Households seeking to address chromium-6 specifically should consider targeted filtration options designed for hexavalent chromium.
Interpreting the Median and Range of Chromium-6 Levels from Public Data
The median detected chromium-6 concentration in this system was approximately 0.545 µg/L (ppb), with values ranging up to 4.9 µg/L. This suggests that while chromium-6 is commonly detected, it generally remains at low levels in the larger distribution network. Individual household measurements might fall anywhere within or outside this range, underscoring the importance of specific testing to inform treatment needs.
Water Quality Symptoms Related and Unrelated to Chromium-6
Certain household issues such as unusual tastes or staining can sometimes be linked to water chemistry changes but are unlikely to specifically indicate chromium-6 presence. Chromium-6 itself is colorless and tasteless at these low concentrations. Therefore, symptoms like discoloration or corrosion more often reflect other water quality factors. Reliable detection requires laboratory analysis rather than relying on sensory symptoms.
Additional Considerations for Commercial or Industrial Operators
Unlike residential users, commercial or industrial facilities may need to evaluate chromium-6 impacts on specific processes, product quality, or regulatory compliance. This involves more frequent or detailed water testing and tailored treatment strategies. Households generally focus on ensuring safe and palatable drinking water, while commercial operations face extended water use considerations.
In summary, the Iredell Water Corporation’s public water system record informs that chromium-6 has been regularly detected at low levels through surface water sourcing, with no federal drinking water violations for total chromium. This data reflects system-wide water quality, not an individual household’s water. For certainty about your local water, testing is essential. To address chromium-6, devices like the C-Series Chromium-6 Filter ship ready to configure for residential use and specifically target hexavalent chromium.
Source: United States Environmental Protection Agency's Safe Drinking Water Information System public water system records and UCMR3 monitoring data for Iredell Water Corporation.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2015-10-29. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Iredell Water Corporation (NC0149025), NC: 180 results across 2 listed contaminants, 104 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L