Fleck Chromium-6 Filter

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Local Water Supply Background

The Waipahu-Ewa-Waianae water system in Honolulu County sources its water primarily from groundwater. This water is treated and distributed to over 40,000 connections serving 217,479 residents. The system's public water record indicates no EPA health-based violations. Chromium-6, also called hexavalent chromium or chromium(VI), has been detected in all sampled results during federal monitoring from 2013 to 2015, but no contamination levels exceed health safety limits.

How Ion Exchange and Reverse Osmosis Affect Hexavalent Chromium

Ion Exchange Treats Chromium(VI) Differently

Ion exchange technology targets chromium-6 by exchanging chromium ions in the water with less problematic ions on a resin medium. This process can reduce hexavalent chromium concentrations effectively at the point water enters the home.

Reverse Osmosis Operates with a Different Mechanism

Reverse osmosis pushes water through a semipermeable membrane, filtering out chromium(VI) among many dissolved solids. RO can remove chromium(VI) alongside other contaminants but works differently from ion exchange, especially in treatment capacity and water waste considerations.

Changes in Chromium Oxidation State from Source to Tap

Chromium Speciation May Vary in the Distribution System

Hexavalent chromium can undergo chemical changes between the wellhead and household taps. Factors like water chemistry and pipeline materials influence whether chromium(VI) remains hexavalent or converts to trivalent chromium (Cr(III)). These oxidation state changes impact how chromium behaves and how it can be treated.

Initial Household Fixtures and Processes Affected

Water Fixtures with High Water Use Are First Influenced

Appliances such as washing machines and dishwashers that rely on municipal water may first exhibit effects from chromium-6 presence because they process large water volumes continuously.

Hot Water Systems May Enhance Chemical Changes

Heating water can alter chromium speciation and influence its solubility and interaction with household plumbing materials.

Long-Term Implications if Chromium-6 Remains Untreated

Potential Accumulation Effects on Household Plumbing

Over years, chromium can contribute to scale or deposition inside pipes, though this varies depending on water chemistry and usage patterns.

Regular Monitoring Essential for Ongoing Awareness

Without specific testing of household water, presence and concentration of chromium-6 remain unknown. Long-term exposure details depend on individual water characteristics.

Sampling Extent and Data Interpretation

System-Wide Data Based on 41 Tested Samples

The chromium-6 data for Waipahu-Ewa-Waianae comes from 41 samples, all detecting chromium(VI) above a reporting level of 0.03 micrograms per liter (ppb). The highest recorded value was 9.7 ppb, with a median of 1.3 ppb.

Data Reflects Public System, Not Specific Household Conditions

These figures represent the entire public water system rather than any individual home's water, so household testing is necessary for precise knowledge.

Why Total Chromium Does Not Fully Describe Chromium-6 Presence

Total Chromium Includes Multiple Chromium Forms

Total chromium measurements combine trivalent chromium (Cr(III)) and hexavalent chromium (Cr(VI)), but these forms differ chemically and in potential effects.

Distinguishing Between Chromium Forms Requires Specific Tests

Knowing total chromium alone does not reveal chromium-6 concentration, which needs targeted analysis for hexavalent chromium species.

What Area Data Does and Does Not Mean for Your Water

• Area measurements indicate the presence of chromium-6 in the water system but do not specify your home's water chemistry.
• No health-based violations or exceedances for chromium-6 have been recorded for this system by EPA standards.
• Testing your home's water is the only way to determine chromium-6 levels specific to your household.
• The Fleck Chromium-6 Filter ships ready to configure and is designed to address chromium(VI) concerns directly at the household point of use.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2015-01-13. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Waipahu-Ewa-Waianae (HI0000335), HI: 82 results across 2 listed contaminants, 81 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L