What a Certified Laboratory Test for Chromium-6 Reports and How to Read It
Result as Measurement, Not Judgment
A certified laboratory report for Chromium-6 quantifies concentration as micrograms per liter (µg/L). The measured value indicates the amount detected in that specific water sample at that moment. It does not declare the water unsafe or safe without context and comparison to standards.
Understanding Reporting Levels
Tests have a reporting level, the lowest concentration reliably measurable — typically 0.03 µg/L for Chromium-6. Values below this are noted as non-detects but do not imply absence, only undetectably low presence.
Interpreting Median and Range
Look for the median, which is the middle value of all detected results, and the reported range from lowest to highest. These provide a sense of typical levels and variability but cannot define your home’s specific concentration.
Questions a Commercial or Industrial Operator Adds That a Household Does Not
Volume and Process Impact
Commercial users inquire about Chromium-6 relating to process needs and large water volume effect. Households generally focus on consumption and aesthetic factors without complex operational dependencies.
Regulatory Thresholds for Compliance
Industries must monitor to comply with various standards and permits, while residential focus remains on knowing water quality for health and appliance care, guided by municipal reports without regulatory action for Chromium-6.
How Public-System Records Differ from Private-Well Testing in What They Establish
System-Wide Data versus Individual Home Conditions
Public water system data, such as those for Indianapolis Water serving over 880,000 people, indicate overall trends and detection frequencies in the treatment system and distribution network, not specific household levels.
Sampling Frequency and Coverage
EPA’s Unregulated Contaminant Monitoring Rule (UCMR3) results for Indianapolis from 2013-2015 showed 59 samples with 39 detections of Chromium-6, highest at 0.41 µg/L. These reflect system-wide surveillance, not a household test.
Health-Based Violations and Limits
No health-based violations for Chromium-6 have been recorded for this system. The total chromium federal maximum contaminant level (MCL) of 100 µg/L is far above detected values, which means regulatory safety thresholds are met.
How Sample Depth, Well Depth, or Source Type Changes Expectations
Source Water Type: Surface Water Influence
Indianapolis Water uses surface water sources. Surface water can fluctuate with environmental conditions affecting Chromium-6 levels differently than groundwater from wells.
Depth and Distribution Networking
Sampling points may vary in depth and location, impacting detected concentrations. Private wells, if tested, might show different values due to distinct geologic and hydrologic conditions.
Why Aesthetic Secondary Standards Differ from Health-Based Limits, Applied to Chromium-6
Understanding Aesthetic Guidelines
Secondary standards for constituents like Chromium-6 concern taste, color, or staining potential and do not reflect health risks. Public system reports focus on health-based standards, which for total chromium are substantially higher.
Chromium-6 and Aesthetic Effects
Chromium-6 at the detected levels in Indianapolis does not trigger aesthetic secondary standards or health-based thresholds, indicating no regulatory concern for appearance or safety.
Summary
Local public water system data clarify detected Chromium-6 levels and their professional context but cannot determine the concentration in any individual household’s water. Obtaining a certified laboratory test of your home water is necessary for that. For addressing Chromium-6, the Fleck Chromium-6 Filter ships ready to configure and helps reduce this constituent effectively for residential use.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2015-12-30. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Indianapolis Water (IN5249004), IN: 118 results across 2 listed contaminants, 49 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L