Geogenic Chromium-6 in Brownsburg’s Surface Water Versus Industrial Sources
The Brownsburg Waterworks system in Hendricks County supplies water drawn from surface sources to over 31,000 people. Hexavalent chromium (chromium-6 or Cr(VI)) can originate from natural geochemical conditions or industrial activities such as plating. In Brownsburg, the EPA’s Unregulated Contaminant Monitoring Rule (UCMR3) found chromium-6 detected at levels up to 0.13 micrograms per liter (µg/L) or parts per billion (ppb). This result arises from routine area monitoring and reflects the system-wide water, not any specific household.
Ion Exchange Versus Reverse Osmosis: Approaches to Chromium(VI) in Water
When addressing chromium-6 specifically, ion exchange and reverse osmosis (RO) employ distinct mechanisms. Ion exchange uses resin media to selectively bind and remove chromium(VI) ions from water, typically allowing higher flow rates and lower water waste. RO forces water through a semipermeable membrane, filtering out chromium-6 by size exclusion and producing highly purified water but often with increased wastewater and maintenance. Each technique targets Cr(VI) effectively but varies in footprint, operation, and water efficiency.
Understanding Certified Laboratory Reports for Chromium(VI)
A certified laboratory test for chromium-6 reports measured concentrations in micrograms per liter. It quantifies chromium-6 apart from total chromium to clarify what form is present. The report typically shows the detection level, numerical result when above that level, and informs if chromium-6 was not detected below the reporting threshold. This detailed analysis helps homeowners decide on treatment needs based on their own water quality rather than regional averages.
Meaning of 'Detected', 'Median', and 'Range' in Brownsburg Waterworks Sampling Data
In the sampling from 2013 to 2015, chromium-6 was detected in 6 out of 20 samples at levels between 0.03 µg/L (the reporting level) and a maximum of 0.13 µg/L, with a median of detections at 0.115 µg/L. 'Detected' indicates the presence above the instrument's sensitivity but is not a violation or safety concern. The median reflects the middle value of positive detections, while the range shows variation over the sampling period. These figures describe system-wide conditions and should not be assumed for individual household taps.
Water Quality at the Tap After Using the C-Series Chromium-6 Filter
Once a C-Series Chromium-6 Filter is configured for a household, the treated water at the tap undergoes targeted removal of Cr(VI) to levels typically well below detectable concentrations. This treatment selectively addresses chromium-6 without significantly altering other water components. The technology integrates ion exchange media designed specifically for hexavalent chromium, offering an approach that conserves water compared to membrane filtration methods. The result is water that aligns more closely with individual preferences and concerns regarding chromium-6 presence.
What Not to Conclude from Area Water Data
It is important to understand that Brownsburg Waterworks’ system-wide chromium-6 measurements do not indicate the exact chromium-6 concentration in any single residential tap. Detection in monitoring is not a health violation or a signal of unsafe drinking water, as no EPA health-based violations are on record for this system. To determine your own water’s chromium-6 level accurately, a certified laboratory test of your household water is necessary. The choice between ion exchange and reverse osmosis treatment for chromium-6 should be based on your test results, water usage patterns, and preferences for maintenance and water conservation. The C-Series Chromium-6 Filter is documented to provide effective chromium(VI) treatment when an elevated presence warrants action.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2013-12-04. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Brownsburg Waterworks (IN5232002), IN: 40 results across 2 listed contaminants, 7 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L