When considering chromium-6 presence in residential water in Pierce County, it is essential to understand what public water system data can and cannot reveal for your household. Data from a large surface water system serving over 64,000 people offers a broad snapshot but does not specify conditions in individual homes or wells. Only direct testing of your own water can accurately determine your household’s chromium(VI) level.
How Ion Exchange and Reverse Osmosis Differ in Addressing Chromium(VI)
Chromium-6, or hexavalent chromium, interacts differently with water treatment technologies. Ion exchange systems typically swap ions in water to target dissolved chromium(VI), offering a targeted approach for this contaminant. Reverse osmosis units physically filter water through a membrane, reducing a broader range of dissolved substances including chromium(VI). Depending on water chemistry and other constituents, these methods vary in efficiency and maintenance demands.
Trivalent Versus Hexavalent Chromium: Why Total Chromium Data Isn’t Enough
The EPA monitoring for this area reports results for both chromium-6 specifically and total chromium. Chromium-6 (hexavalent chromium) is chemically different and can be present in varying proportions relative to trivalent chromium (chromium(III)). The total chromium measure does not distinguish between these forms. Since hexavalent chromium is the species of concern for this issue, relying on total chromium alone will not provide a clear picture of potential chromium-6 presence.
Impact of Sample Depth, Well Depth, and Source Type on Expected Chromium Levels
Water from surface sources, like the one serving the Southwood Water System in Pierce County, generally differs from groundwater in chromium characteristics. Depth of wells or sampling points can influence the observed chromium-6 concentrations due to geologic and environmental factors. Surface water sources might display different seasonal fluctuations and contaminant profiles compared to deep wells.
Seasonal and Multi-Year Variation in Chromium-6 as Seen in Local Monitoring
The EPA data collected from August 2014 through March 2015 show chromium-6 detections in 33 of 41 samples with concentrations ranging up to 0.23 micrograms per liter (µg/L or ppb). Median detected levels were 0.11 µg/L. These values are single measurements from a federal occurrence survey, reflecting a snapshot over multiple months rather than long-term trends. Seasonal variation and subsequent years’ data could differ, underscoring the importance of current household testing rather than assuming static conditions.
How Chromium-6 Differs from Commonly Confused Water Issues
Chromium-6 in water should not be confused with other water concerns such as total dissolved solids, metals like iron or manganese, or microbial contaminants. Chromium-6 is a distinct chemical species requiring specific consideration. Its presence at low levels does not imply unsafe water, nor does it indicate other water quality problems.
Conclusions and What You Should Not Assume from Area Data
The regional data for this Pierce County water system show no record of health-based violations for chromium-6 or total chromium. Detected concentrations are well below any federal maximum contaminant levels for total chromium. However, these area-wide findings do not identify the exact level at your residence. To understand your domestic water condition, you would need a direct water test specifying chromium-6. If you seek targeted performance for managing hexavalent chromium, the Fleck Chromium-6 Filter ships ready to configure and is designed to address this constituent specifically.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2015-03-16. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Southwood Water System (WA5382844), WA: 82 results across 2 listed contaminants, 49 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L
- ✓ 90-Day Money-BackNo restocking fees — return within 90 days.
- ✓ Manufacturer WarrantyGenuine Fleck · Pentair · VIQUA equipment.
- ✓ Free Expert SizingTalk to a specialist and buy the right system the first time.