Chromium-6 in DC Household Water: Understanding Local Levels and Treatment Options

Fleck Chromium-6 Filter

Buy Now

View full details

Understanding What Total Chromium Measurements Mean for Your Home Water

In Washington, DC, the Bolling Water System serves residents with water sourced through a public supply network. Government data from 2013-2015 federal monitoring shows that chromium-6—hexavalent chromium, a form of chromium identified as chromium(VI)—was detected in all sampled instances, with levels ranging up to 0.091 micrograms per liter (µg/L), equivalent to parts per billion (ppb). Total chromium, which includes all valence states like trivalent chromium (Cr(III)) and chromium(VI), showed no detections above 0.2 µg/L in the same samples. Because total chromium measurements do not distinguish between chromium types, a total chromium result alone cannot determine chromium-6 presence or concentration in your household water.

Geogenic Versus Industrial Sources of Hexavalent Chromium

Hexavalent chromium can originate from natural geological sources, particularly in certain aquifers characterized by arid conditions and alkaline pH, or from anthropogenic sources such as industrial processes including plating. The Bolling Water System's reported chromium-6 detections suggest its presence in the regional water but do not specify source type. Understanding whether chromium(VI) in your water stems from natural or industrial origins requires further localized testing beyond system-wide surveys.

California’s 10 µg/L Limit and Its Implications for DC Homes

California has established a public health goal and regulatory limit of 10 micrograms per liter for chromium-6—a precautionary benchmark shaped by research specific to that state. Although this limit does not apply federally or directly to DC’s water systems, it provides context for considering chromium(VI) concentrations. The levels detected by EPA monitoring in DC’s Bolling Water System are well below this benchmark, indicating a substantially lower chromium-6 presence relative to California’s regulatory focus.

Contrasting Ion Exchange and Reverse Osmosis for Addressing Chromium(VI)

When comparing treatment approaches for hexavalent chromium, ion exchange and reverse osmosis offer different mechanisms:

• Ion Exchange: This method uses resin beads to selectively capture chromium(VI) ions from water, effectively reducing hexavalent chromium concentrations. Ion exchange systems like the Fleck Chromium-6 Filter ship ready to configure for residential use.
• Reverse Osmosis: This technique forces water through a semipermeable membrane, removing a broad range of dissolved solids, including chromium(VI). While effective for chromium-6, reverse osmosis also reduces other minerals, which may affect water taste and composition.

Signs in Your Household Water Potentially Linked to Chromium-6 Presence

Hexavalent chromium itself is colorless and tasteless, so visual or sensory signs alone cannot reliably indicate its presence. Common household symptoms such as staining, discoloration, or unusual taste generally stem from other water quality factors and do not specifically point to chromium(VI). To clarify chromium-6 status in your household water, a direct test measuring chromium(VI) concentration is necessary.

The Key Test to Confirm Chromium(VI) Levels in Your Water

To determine the precise chromium-6 concentration in your home, request a certified water analysis that specifically quantifies hexavalent chromium or chromium(VI). This is the single test that can establish your water’s chromium-6 level with certainty and help you decide if any treatment is advisable.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2014-05-19. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Bolling Water System - Jt. Base Anacostia-Bolling (DC0000007), DC: 16 results across 2 listed contaminants, 8 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L