Pentair Chromium-6 Filter

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The difference between hexavalent and total chromium: why total chromium numbers alone won’t clarify chromium-6 levels

Chromium in water occurs mainly in two forms: trivalent chromium (chromium-3), which is a common nutrient at low levels, and hexavalent chromium (chromium-6), which is measured separately in some tests due to different chemical behavior. Total chromium values combine these forms but do not specify chromium-6 concentrations. For example, Portsmouth Waterworks recorded total chromium with a highest measurement of 0.72 micrograms per liter (µg/L), while chromium-6 reached up to 0.46 µg/L. Understanding chromium-6 specifically requires targeted testing because relying on total chromium data alone cannot establish the chromium-6 present in household water.

What the UCMR3 federal survey was designed to learn and its limitations for assessing one household’s water

The 2013–2015 third Unregulated Contaminant Monitoring Rule (UCMR3) survey provides a snapshot of chromium-6 levels in the Portsmouth municipal surface water system serving approximately 33,000 people. It was intended to gather data on contaminants without legal maximum contaminant levels (MCLs) to possibly inform future regulations. However, its results represent averages and detection rates system-wide, not specific residences. While 16 of 18 chromium-6 samples registered detectable levels (above 0.03 µg/L), these are not violations or indications of unsafe water but measurements. Homeowners interested in their particular water quality must arrange individualized testing to determine their own chromium-6 concentration.

Why aesthetic secondary standards differ from health-based limits in the context of chromium

Chromium-6 has no federal MCL under the Safe Drinking Water Act, and total chromium has a regulatory MCL of 100 µg/L (100 parts per billion). The detected chromium-6 levels in Portsmouth are well below these health-based thresholds. Some secondary standards exist for aesthetic effects such as taste or staining related to total dissolved solids and chloride, but these do not indicate health risks and are unrelated to chromium-6 measurements. Homeowners concerned about taste or appearance should consider separate testing and treatment options targeting those parameters.

Geogenic versus industrial sources of hexavalent chromium: what local geology and activities imply

Hexavalent chromium can arise from natural geochemical processes, especially in arid or alkaline groundwater aquifers, or can originate from industrial activities such as metal plating. Portsmouth’s surface water source and regional data do not directly indicate widespread industrial chromium-6 contamination. Understanding local geology and water source history can help clarify the likely presence and levels of chromium-6, though only direct household water testing can confirm that.

Household symptoms that do and do not indicate chromium-6 presence

Chromium-6 is colorless and odorless and does not cause immediate aesthetic changes such as discoloration or taste. Symptoms such as staining or unusual taste in water generally point to other substances. Concerns about chromium-6 are based on long-term exposure studies and cannot be identified by sensory detection or typical household observations. Testing remains the only way to assess chromium-6 levels in a household’s water.

How the Pentair Chromium-6 Filter addresses chromium(VI) concerns in residential water

The Pentair Chromium-6 Filter ships ready to configure for home water systems and is designed specifically to target hexavalent chromium. It employs proven filtration technology that effectively reduces chromium(VI) concentrations, thus providing an option for homeowners weighing treatment approaches. Using this filter can help households manage chromium-6 levels measured by testing, complementing decisions based on water system data and individual needs.

In closing, the Portsmouth Waterworks public system record provides useful regional chromium-6 data but does not reflect conditions in individual household water. Homeowners should pursue dedicated testing to understand their water quality. For detailed federal records, the EPA’s UCMR3 data for Portsmouth Waterworks is the authoritative source.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2015-04-07. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Portsmouth Waterworks (NH1951010), NH: 36 results across 2 listed contaminants, 31 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L