Understanding Chromium-6 Presence in Westerly, Washington County, RI Water

This week, you need to decide if your household water in Westerly, Washington County, Rhode Island requires testing for chromium-6, also known as hexavalent chromium or chromium(VI).

Nationwide Survey Goals and Household Limits

EPA's UCMR3 Data Collects Broad Area Information

The 2013-2015 Unregulated Contaminant Monitoring Rule (UCMR3) sampled public water systems including Westerly Water Department. It identified chromium-6 in all 16 samples tested, with levels ranging from 0.03 to 0.26 micrograms per liter (µg/L or parts per billion). This is a measurement, not a safety threshold or violation.

Survey's Design Does Not Establish Individual Household Levels

While the survey provides a general picture for the municipal groundwater supply serving about 35,300 people, it does not specify chromium-6 concentrations in any single home or tap. Local plumbing and point-of-entry factors can alter exposure.

Commercial-Industrial Water Use Considerations

Operators Consider Process Impact and Regulatory Oversight

Unlike residential users, commercial or industrial users evaluate chromium(VI) levels for compliance and operational effects. Their concerns include possible wastewater discharge limits and product quality, which households typically do not need to address.

Testing Frequency and Scope Are More Stringent

Businesses often conduct more frequent and varied testing than the once-every-five-years approach of UCMR3, targeting multiple contamination points beyond source water.

Large or Seasonal Household Variables

Properties with Higher Water Use May Track Trends Differently

Large families or second homes might observe water quality changes that differ from average municipal data due to water age in the system or building-specific plumbing conditions.

Seasonal Properties May Experience Variations in Water Chemistry

Fluctuations in chromium-6 levels can occur seasonally in groundwater. Testing before reoccupation is advisable to understand current conditions.

Aesthetic Standards vs. Health-Based Limits

Chromium-6 Has No Federal Maximum Contaminant Level

While total chromium has an EPA MCL of 100 µg/L, chromium-6 itself lacks a federal health-based limit. The detected levels in Westerly are well below this and should not be interpreted as unsafe.

Aesthetic Guidelines Address Taste and Appearance, Not Health

Secondary standards for water quality consider factors like color or corrosion but do not set enforceable health limits for chromium-6.

Distinguishing Chromium-6 from Similar Concerns

Chromium(VI) Is Different from Total Chromium Measurements

Total chromium includes multiple oxidation states; chromium-6 is one specific, more chemically active form. Testing for total chromium alone may miss important distinctions relevant to health and treatment.

Chromium-6 Is Chemically Distinct from Other Metals

Do not confuse chromium-6 with other metallic contaminants or water quality issues such as iron or manganese, which have different sources and effects.

How the C-Series Chromium-6 Filter Addresses Water Concerns

Specialized Filtration Targets Hexavalent Chromium

The C-Series System uses technology designed to reduce chromium(VI) concentrations in household water, improving quality where testing confirms elevated levels.

Ships Ready to Configure for Home Use

This equipment arrives prepared for user setup without requiring professional service, providing a controllable layer of treatment for chromium-6.

The essential next step is to order a certified laboratory test specifically for chromium-6 in your home water supply. A result below the UCMR3 detection range (under 0.03 µg/L) indicates very low chromium(VI) presence. Should levels be higher, consideration of a targeted filtration approach like the C-Series Chromium-6 Filter can help address the concern effectively.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2015-09-16. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Westerly Water Department (RI1559512), RI: 32 results across 2 listed contaminants, 19 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L