If you notice a metallic taste or slight discoloration at your faucet in Bismarck, part of Burleigh County, chromium-6 (hexavalent chromium) could be a factor. While no health-based violations have been recorded for chromium in the City of Bismarck's public water system, federal monitoring found chromium-6 detectable in all tested samples between 2013 and 2015. This page helps you understand what those results mean for your household water.
Geogenic Hexavalent Chromium in Arid and Alkaline Aquifers Versus Industrial Plating Sources
Chromium-6 found in water systems can originate from very different sources. In regions like Burleigh County, chromium-6 presence in surface water mainly results from natural geological processes, specifically from oxidized chromium minerals in arid, alkaline aquifers or soils. This geogenic source contrasts with industrial plating-related chromium-6 contamination often found near manufacturing sites. Burleigh County's surface water is more influenced by these natural sources than industrial discharge, which helps contextualize the chromium-6 detected by EPA monitoring.
How Oxidation State Changes Between the Well, the Distribution Main and the Tap
Chromium's oxidation state can shift as water travels from its source to your tap. Chromium-6 (Cr(VI)) is the oxidized form, more soluble and mobile, but it can reduce to chromium-3 (Cr(III)) during distribution, especially under certain chemical and biological conditions. This transformation can alter chromium's concentration and form by the time water reaches your household. Since Bismarck's water system relies on surface water sources and treatment processes, variations in chromium speciation are expected along the supply chain, suggesting your tap water’s chromium-6 concentration may differ from raw water samples.
How Seasonal or Multi-Year Variation Shows in the Record (Dates and Ranges Given)
The EPA's Unregulated Contaminant Monitoring Rule 3 (UCMR3) results for Bismarck’s system, collected from May 2013 to February 2014, show chromium-6 detected at levels ranging from just above 0.03 micrograms per liter (µg/L) to a high of 0.7 µg/L, with a median around 0.6 µg/L. These values indicate the presence of chromium-6 but do not specify health risks as no federal maximum contaminant level exists for hexavalent chromium. Seasonal factors such as rainfall, temperature, and changes in water source usage can influence these concentrations year to year, so chromium-6 levels currently in your water could vary from historic measurements.
What Questions a Commercial or Industrial Operator Adds That a Household Does Not
Commercial and industrial water users often require chromium-6 data for compliance with workplace safety regulations or discharge permits, focusing on higher volume usage and potential industrial processes contributing to chromium presence. Such operators may test more frequently and analyze chromium speciation in greater detail to manage corrosion, product quality, and regulatory reporting. Households, however, typically focus on understanding water quality for everyday use and possible aesthetic effects, making broader system data and targeted home testing for chromium-6 more relevant.
How the Treated Water Differs at the Tap Once the Documented Technology Is in Place
When household water is treated with a Fleck Chromium-6 Filter, chromium-6 levels can be effectively lowered through a proven filtration technology that targets hexavalent chromium specifically. This direct-purchase system ships ready to configure for home use and provides a barrier to chromium-6 reaching your taps. While the original water profile may show chromium-6 concentrations detected by federal monitoring as detailed earlier, the treated water at the tap shows markedly diminished chromium-6 content, improving water taste and potentially addressing concerns related to chromium-6 presence.
Trivalent Versus Hexavalent Chromium: Why a Total-Chromium Result Cannot Answer the Question
Total chromium measurements combine chromium-3 and chromium-6 forms, but these differ significantly in chemistry and behavior. Chromium-3 is an essential nutrient with low mobility, whereas chromium-6 is more soluble and reactive. The EPA’s monitoring showed total chromium levels well below 1 µg/L in Burleigh’s water system, far beneath the 100 µg/L federal standard for total chromium. However, knowing total chromium alone cannot reveal the hexavalent chromium fraction responsible for specific water quality effects. Therefore, specialized testing for chromium-6 is necessary to understand the form affecting your water.
What You Should Not Conclude From Area Data: The Seattle-area public water system record reflects broad community water quality and not the specifics of your home’s water. Detection of chromium-6 in federal samples is not a violation or a safety determination. Individual water testing is essential to know your household's chromium-6 level. While the Fleck Chromium-6 Filter offers a documented way to address chromium-6, no on-site assessment has been made, and the system’s public record shows no health-based violations or federally enforceable chromium-6 limits. Staying informed and testing your water remain the best steps toward understanding your household’s water quality.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2014-02-11. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for City of Bismarck (ND0800080), ND: 16 results across 2 listed contaminants, 16 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L