Myth: Chromium-6 Levels Remain the Same from Source to Tap
It is commonly assumed that chromium-6 concentrations measured at the water source are consistent throughout the distribution system and at your faucet. However, the oxidation state of chromium can change as water moves from surface sources through treatment processes and pipes to your home. This means chromium(VI) may convert to other chromium forms by the time it reaches your tap, affecting its chemical behavior and potential impact. Understanding these changes requires a household-specific water test, as regional findings cannot predict the exact condition in your home.
Myth: Total Chromium Measurements Provide Complete Information About Chromium-6 Risks
Many believe that total chromium levels alone clarify chromium-6 concerns, but total chromium includes both trivalent chromium (chromium-III) and hexavalent chromium (chromium-6). The EPA data for Des Moines Waterworks shows total chromium detections with a median around 0.45 micrograms per liter (µg/L), while chromium-6 detections have a median near 0.22 µg/L. This means less than half of the measured total chromium is chromium-6, which has different chemical properties and health considerations. Therefore, relying solely on total chromium data does not specify chromium-6 presence or concentration.
Myth: Chromium-6 Concerns Are the Same as Those for Iron or Other Metals
Chromium-6 issues are often confused with problems from metals like iron, but they differ significantly. Chromium-6 is a distinct chemical form of chromium that can affect water color and taste differently, and may have separate treatment needs. Iron is typically addressed for staining and metallic taste, while chromium-6 is primarily monitored due to its unique chemistry. The EPA’s Unregulated Contaminant Monitoring Rule 3 (UCMR3) data clarifies chromium-6 levels independently of these other metals, underscoring the importance of targeted testing and treatment strategies.
Myth: The Faucet or Fixtures Are Not Affected by Chromium-6 Levels
Some believe that household fixtures and appliances are unaffected by chromium-6, but certain water-using devices can interact differently with chromium-6 depending on water chemistry. Chromium-6 may influence corrosion rates or contribute to buildup in pipes and appliances over time, potentially impacting water quality and equipment longevity. Faucets with aerators and ice makers or humidifiers drawing water directly from taps may register chromium-6 effects earlier, making targeted treatment a consideration for protecting sensitive fixtures.
Myth: The UCMR3 Data Fully Defines Chromium-6 Exposure for a Single Home
The UCMR3 data from 2013–2015, including 24 chromium-6 samples for Des Moines Waterworks, offers valuable regional insight but has limits for individual households. This federal occurrence survey aimed to measure contaminant presence broadly rather than test compliance or safety at individual taps. With detections ranging up to 2.62 µg/L and median detections near 0.22 µg/L, the data shows measurable chromium-6 across the system. Yet, a specific household’s chromium-6 level depends on factors such as water source variations, plumbing materials, and treatment devices. Testing your own water is necessary for accurate assessment.
Solutions for Managing Chromium-6 in Household Water
If water testing reveals chromium-6 levels in your household water that you wish to address, the Autotrol Chromium-6 Filter ships ready to configure for residential use. This technology is designed to preferentially target chromium(VI), easing concerns developed from regional monitoring findings by effectively treating chromium-6 across typical household water volumes. It complements informed decision-making based on measured demand and individual water quality test results, helping you manage chromium-6 reliably within Polk County’s local water conditions.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2015-04-01. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Des Moines Waterworks (IA7727031), IA: 48 results across 2 listed contaminants, 32 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L