Chromium-6 Water Information and Treatment Options for New Haven, CT Households

1. Chromium-6 Levels from Source to Tap in New Haven County

The Regional Water Authority of New Haven County, serving Ansonia, Bethany, Branford, Cheshire, Derby, East Haven, Hamden, Meriden, Milford, New Haven, North Branford, North Haven, Orange, Prospect, Seymour, Southington, Wallingford, West Haven, Wolcott, and Woodbridge, obtains its supply from surface water. According to EPA UCMR3 monitoring from 2013 to 2015, chromium-6 (also called hexavalent chromium or chromium(VI)) was detected in 35 of 36 samples above 0.03 micrograms per litre (µg/L), also one part per billion (ppb). The highest measured chromium-6 level was 0.86 µg/L, while the median detection was 0.2 µg/L. These values reflect the water at the distribution system level but do not provide specific information about the water inside any individual household's plumbing.

2. Purpose and Scope of the UCMR3 Chromium-6 Monitoring

The Unregulated Contaminant Monitoring Rule 3 (UCMR3) was a nationwide federal project designed to identify the frequency and range of several contaminants, including chromium-6, in public water systems. This monitoring was not a compliance test nor meant to diagnose water quality in individual homes. The data helps federal and state agencies understand contaminant prevalence but does not replace testing for specific wells or taps.

3. What the Chromium-6 Measurements Mean Compared to Federal Standards

Federal regulations have a maximum contaminant level (MCL) of 100 µg/L for total chromium, which includes both chromium-3 and chromium-6 forms. The detected chromium-6 concentrations in New Haven County’s surface water source were well below this regulatory level. There is currently no federal MCL specific to chromium-6, so the presence of chromium-6 at these measured levels does not imply a violation or health-based concern. Detected concentrations are measurements informing water managers and consumers but are not direct indicators of a health risk.

4. Influence of Plumbing Materials and Age on Chromium Levels at the Tap

Water chemistry can change between the water main and the tap due to reactions within the household plumbing system. Older pipes or certain materials may affect metal concentrations, including chromium species, by leaching or by chemical transformations. Because the publicly reported figures are from the distribution system, they do not account for variations introduced by individual plumbing. Understanding this distinction is important when choosing treatment equipment to address chromium-6 concerns specifically at the tap.

5. Household Signs That May Indicate Chromium-6 Presence or Non-Related Issues

Chromium-6 itself is colorless and does not cause taste or odor changes in water, so its presence does not produce obvious sensory symptoms. Problems like staining or metallic taste are more typically linked to other constituents. Thus, if you notice discoloration or unusual tastes, these may not be related to chromium-6 and should be evaluated separately. Conversely, the absence of sensory symptoms does not confirm chromium-6 absence.

Final Step: Testing to Confirm Chromium-6 Levels in Your Home

To determine the chromium-6 concentration in your household water, a specific water test for chromium-6 or hexavalent chromium must be performed on a sample drawn from your tap or well. This test result is the definitive measure to guide your treatment decision. If chromium-6 is detected at levels of concern to you, treatment equipment such as the Pentek Chromium-6 Filter ships ready to configure and can address chromium-6 effectively in residential settings.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2014-10-21. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Regional Water Authority (CT0930011), CT: 72 results across 2 listed contaminants, 64 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L