Autotrol Chromium-6 Filter

Buy Now

View full details

Local chromium oxidation states can change from source to tap

Chromium in water presents primarily in two oxidation states: trivalent chromium (chromium III) and hexavalent chromium (chromium VI). In Lehigh County, the public water system LCA-WLSA Central Division draws from surface water, where chromium can exist in different forms. Chemical and physical processes occur between the source water, treatment, distribution mains, and the household tap, altering the chromium’s oxidation state. This means that chromium(VI) concentrations measured in source or treatment water may not exactly match what reaches individual taps. Testing your home's water is the only way to determine your specific chromium forms and levels.

Total chromium values do not specify chromium(VI) presence conclusively

Government sampling in this system shows all detected chromium values are below the total chromium federal maximum contaminant level (MCL) of 100 micrograms per liter (µg/L), or parts per billion (ppb). However, total chromium measures both trivalent chromium and hexavalent chromium combined. Trivalent chromium, a nutrient in small amounts, differs chemically and toxicologically from chromium(VI), which is more mobile and reactive. Therefore, knowing total chromium alone does not reveal how much chromium(VI) is present. Specific testing for chromium-6 is necessary to understand its occurrence accurately.

Ion exchange and reverse osmosis address chromium(VI) differently

Treatment technologies available for addressing chromium(VI) vary in approach and effectiveness. Ion exchange works by exchanging chromium(VI) ions in water with other ions on resin beads, targeting the hexavalent species selectively. Reverse osmosis (RO), on the other hand, forces water through a semipermeable membrane that blocks chromium(VI) particles along with other dissolved solids. Each method has different operational characteristics, maintenance needs, and impacts on water use. For a residential setting, choosing between ion exchange and RO depends on water chemistry, household water consumption, and treatment goals.

Estimating treatment needs based on daily household water use

When evaluating treatment options for chromium-6, understanding your household’s daily water demand is crucial. Treatment capacity must align with average and peak water use to maintain performance and water quality. For example, ion exchange media has a finite capacity before regeneration is required, whereas RO units produce treated water at a constant throughput rate but generate wastewater. Assessing your household’s average gallons per day informs what scale and technology of treatment will meet your needs.

Commercial and industrial water users have additional considerations beyond residential

While this page focuses on residential concerns, commercial and industrial operators in Lehigh County may face regulatory and operational demands beyond typical household use. Their larger water volumes, discharge requirements, and potential for chromium processing necessitate more comprehensive monitoring and tailored treatment strategies. Such facilities may require continuous chromium(VI) monitoring, specialized treatment trains, or compliance reporting not typically needed for a home setting.

Household plumbing materials and age can influence chromium levels separate from source water

Plumbing systems themselves can affect chromium occurrence. Older pipes, solder, or fixtures may contribute trace metals through corrosion or material leaching unrelated to source water chromium levels. Conversely, modern plumbing materials are designed to minimize metal release. Therefore, the chromium-6 found at the tap might reflect household plumbing conditions as well as water system composition. Testing at the tap accounts for these variables.

What local data does not tell you about your home's chromium-6 levels

The EPA sampling data for Lehigh County’s public water system indicates chromium-6 was detected in all samples between 0.03 and 0.74 µg/L, but no health-based violations for chromium or chromium-6 are on record. This federal sampling was a monitoring survey, not a regulatory compliance test, and it does not represent your specific household water. To determine if chromium(VI) in your tap water warrants treatment, direct testing of your water is necessary. If treatment is desired or recommended, the Autotrol Chromium-6 Filter ships ready to configure for home use, providing targeted reduction of hexavalent chromium through proven technology.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2014-12-11. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for LCA-WLSA Central Division (PA3390073), PA: 120 results across 2 listed contaminants, 120 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L