What Regional Water Data Can and Cannot Tell You About Chromium-6
If you live in Kennebunk, Kennebunkport, Wells, or elsewhere in York County, ME, you may be concerned about chromium-6 in your household water. Federal sampling done from 2013 to 2015 by the Kennebunk, Kennebunkport & Wells Water District, which serves over 35,000 people via surface water sources, provides a snapshot of chromium-6 levels in this public system. However, these results represent the water entering the distribution system—not the water at your particular tap or well. To know the chromium-6 concentration in your home water, you would need a water test performed on your own supply.
Trivalent Versus Hexavalent Chromium: Why Total Chromium Results Are Not Enough
The chromium measured in water comes in multiple forms. Chromium-6, also called hexavalent chromium or chromium(VI), differs significantly from trivalent chromium (chromium(III)) in chemical behavior and health considerations. Total chromium testing measures both forms combined and does not distinguish hexavalent chromium presence or levels. The Kennebunk, Kennebunkport & Wells system data shows no total chromium detections above the reporting level of 0.2 micrograms per liter (µg/L), but separate chromium-6 sampling found detections at levels between 0.03 and 0.19 µg/L. Thus, total chromium tests alone cannot answer questions about chromium-6 exposure.
Geogenic Versus Industrial Sources of Hexavalent Chromium
Hexavalent chromium in water arises from natural geological sources or from industrial activities like metal plating. The Kennebunk, Kennebunkport & Wells Water District uses surface water, which can reflect land runoff and natural mineral content rather than groundwater aquifer chemistry. The area’s geological profile is not characterized by arid or alkaline aquifers, where natural chromium-6 presence is more common. Industrial influences on chromium-6 levels vary regionally and can affect water differently than geogenic sources.
Sample Size and What a Small Number of Data Points Mean
The 2013-2015 federal monitoring included 12 chromium-6 samples for this water system, with 8 detections above the reporting level of 0.03 µg/L. While this data shows that chromium-6 is present at low levels in the system, the relatively small sample count means the data is an indicator, not a comprehensive coverage of all water sources or time periods. Variability over time and among different taps or wells cannot be ruled out based on this sample set alone.
California’s 10 µg/L Chromium-6 Limit: Historical Context and Its Relevance
California has established a public health goal for chromium-6 in drinking water at 10 µg/L (parts per billion). This limit is a state-level standard influenced by local research and regulatory considerations. The Kennebunk, Kennebunkport & Wells system’s chromium-6 concentrations, as sampled federally, fall well below this 10 µg/L threshold, with highest recorded at 0.19 µg/L. However, no federal maximum contaminant level (MCL) exists for chromium-6 nationally, making state thresholds a point of reference but not a federal compliance requirement.
Implications for Larger Households, Second Homes, and Seasonal Properties
Water use patterns and treatment needs can differ for larger families or for households that are occupied seasonally. Such variations can influence factors like water demand, pipe stagnation time, and the potential need for filtration tailored to chromium-6. Properties that use private wells, rather than the municipal system, should consider individual testing, as local variations could affect chromium-6 levels differently than the regional public supply data indicates.
Distinguishing Chromium-6 Issues from Commonly Confused Water Concerns
Chromium-6 is often confused with other water quality concerns but is chemically distinct from total dissolved solids, iron, or sulfate issues that can affect taste, odor, or staining. Unlike microbiological problems or organic contaminants, chromium-6 is a chemical constituent measured in micrograms per liter, requiring specific analytical methods. Understanding this distinction helps target appropriate testing and treatment strategies.
What You Should Not Conclude from Regional Data
Although area-wide water sampling shows chromium-6 presence at low levels in the Kennebunk, Kennebunkport & Wells Water District system, this does not establish the concentration or risk for any individual residence. The absence of federal health-based violations on record indicates that the public water system meets current regulatory standards. Individual testing remains the only way to determine your household’s chromium-6 levels. For residents looking for treatment options, equipment like the C-Series Chromium-6 Filter ships ready to configure and is designed specifically to address hexavalent chromium concerns in home water supplies.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2014-12-03. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Kennebunk, Kennebunkport & Wells WD (ME0090760), ME: 24 results across 2 listed contaminants, 8 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L