1. How Chromium-6 Changes from Groundwater to Your Tap
Chromium in water exists in several chemical forms, with chromium-6 (hexavalent chromium, Cr(VI)) being distinct due to its oxidation state. This form can transform naturally as water moves from the well through the distribution system to your faucet. Factors like oxygen levels and treatment processes may alter the chromium species, but they do not eliminate chromium entirely. Therefore, measurements at the tap can differ somewhat from well or source water levels.
2. Sources of Hexavalent Chromium: Natural Versus Industrial
In Lincoln Parish, public records report chromium-6 in groundwater from Ruston Water System, which relies on groundwater sources. The aquifers here tend to be more alkaline and can contain naturally occurring chromium-6 as part of geogenic processes, distinct from chromium released by industrial activities like plating. Recognizing whether chromium-6 stemmed from natural geology or industrial discharges involves local environmental data and history, but the public water system's data integrates these influences without specifying the source.
3. Plumbing Materials and Age: Effects Separate from Source Water
The composition and age of household plumbing can influence chromium forms present at your tap independently of source water chemistry. For instance, older pipes or certain materials can leach metals or interact with water chemistry, potentially altering chromium levels. However, the public water system monitoring primarily reflects source water quality before household plumbing impact, so additional testing at your home may be necessary to understand in-home contributions.
4. Comparing This Area's Chromium-6 Record with Nearby Counties
Ruston Water System’s chromium-6 monitoring from 2013 to 2015 shows 7 detections above the reporting level (0.03 micrograms per liter or parts per billion) out of 37 samples. The highest detected concentration was 0.14 µg/L. Nearby counties may report different detection frequencies or levels, but these differences reflect local hydrogeology, industrial activity, and water system characteristics. It is important not to assume your water matches neighboring areas simply because they are close geographically.
5. Public System Data Versus Private Well Testing
Public water system records cover water quality at the system level, representing averages or samples across many connections. Ruston Water System serves over 22,000 residents through more than 8,000 connections, so results provide an overview of water quality as treated and distributed to many. Private well testing is the only way to confirm chromium-6 levels within your own water supply and household plumbing. Public system data is not a substitute for individual well testing.
6. Applying Public Record Data to Your Household: A Practical Example
Reviewing the Ruston Water System’s chromium-6 detections, the median detected concentration was about 0.05 µg/L with some variation up to 0.14 µg/L. Since the federal total chromium maximum contaminant level is 100 µg/L and no health-based violations exist for chromium-6 in this system, these detected amounts do not represent legal exceedances or documented safety concerns. For a homeowner, these data illustrate the presence and scale of chromium-6 naturally found or introduced in local groundwater but do not specify your tap water’s exact concentration.
Next Step: Confirm Your Household Chromium-6 Level
The only definitive way to understand chromium-6 in your home water is to request a laboratory test for hexavalent chromium on a sample taken directly from your faucet. This test result will clarify whether chromium-6 levels warrant action or equipment. If choosing treatment equipment, the C-Series Chromium-6 Filter ships ready to configure and is designed specifically to address chromium-6 presence at residential scale based on proven technology, providing you with an informed option for water quality control.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2015-01-12. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Ruston Water System (LA1061017), LA: 74 results across 2 listed contaminants, 7 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L