Autotrol Chromium-6 Filter

Buy Now

View full details

What the UCMR3 Nationwide Survey Measures and What It Does Not

Designed to Characterize Public Water System Occurrence

The EPA's Unregulated Contaminant Monitoring Rule (UCMR3) survey collected chromium-6 data for the Exeter Water Department system serving Rockingham County residents between 2013 and 2015. This sampling focused on the public water system's surface water sources and distribution network to establish presence and concentration ranges of chromium(VI) across multiple points.

Limits for Determining Individual Household Levels

Because the survey's scope encompasses the entire community served, it cannot specify chromium-6 concentrations in any one home’s water supply. Variations after the main distribution and through individual plumbing can alter levels, so personal water testing is necessary to identify your own household conditions.

Oxidation State Changes from Source to Tap

Chromium Speciation in Water Systems

Chromium appears in various chemical forms, with chromium-6 (hexavalent chromium or Cr(VI)) being one type detected in the Exeter system. Water treatment and distribution can influence hexavalent chromium’s oxidation state, sometimes converting Cr(VI) to other chromium forms, affecting its measured concentration at the tap.

Impact on Detection and Measurement

This dynamic chemistry means that the chromium-6 levels measured at water intake or system sampling points may differ from those present in household supplies, highlighting the importance of direct testing at the tap for accurate chromium(VI) assessment.

Stepwise Approach to Testing and Diagnosis

Begin with Basic Household Checks

Start by verifying your existing equipment’s performance and reviewing any local water quality reports to understand the general presence of chromium-6 in the public supply.

Order Laboratory Testing for Hexavalent Chromium

To determine your household’s specific chromium(VI) concentration, request a certified laboratory test for chromium-6 or hexavalent chromium. This is the only way to confirm your water’s condition relative to the area-wide data.

Consider Total Chromium Testing

Testing for total chromium (which includes all chromium forms) can provide additional context but does not substitute for specialized chromium-6 analysis.

Distinguishing Aesthetic Secondary Standards from Health-Based Limits

Understanding Regulatory Context

Exeter’s public water system has reported chromium-6 detections up to 0.046 micrograms per liter (µg/L or ppb) and total chromium up to 0.59 µg/L during the UCMR3 period. The federal Environmental Protection Agency (EPA) has not set a maximum contaminant level (MCL) for chromium-6 specifically, while the MCL for total chromium is 100 µg/L.

Implications for Consumer Concerns

Chromium-6 concentrations found in Exeter water are well below the total chromium MCL, and no health-based violation for chromium has been recorded for the water system. Secondary standards related to taste, staining, or corrosivity are separate and do not indicate a safety issue for chromium(VI).

Scope and Sample Size Behind the Available Data

Number of Samples and Detections

The data for chromium-6 derives from 16 samples collected by the public water system, with 6 samples showing detectable chromium(VI) above the reporting level of 0.03 µg/L. The median detected value was 0.035 µg/L. For total chromium, 2 detections out of 16 samples were above the reporting level of 0.2 µg/L, with a median detected concentration of 0.454 µg/L.

Significance of a Small Sampling Pool

The relatively modest number of samples means the reported concentrations offer a general indication of chromium(VI) presence in the system rather than a definitive profile of every connection or tap within Exeter.

Closing Recommendation: The Essential Test

For households experiencing chromium-6 concerns beyond what their current equipment can handle, the key step is to obtain an individual water test specifically for chromium(VI). A result within or near the range reported for the Exeter system confirms local typical exposure, while a higher level indicates a need for tailored water treatment.

To effectively address chromium-6 at the household level, one documented approach is the use of an Autotrol Chromium-6 Filter, which ships ready to configure and can augment existing water treatment to better manage hexavalent chromium in your home's water supply.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2014-03-04. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Exeter Water Department (NH0801010), NH: 32 results across 2 listed contaminants, 8 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L