What Iron Levels Measured in Madison County Tell Us and What They Do Not
The U.S. Geological Survey (USGS) conducted groundwater sampling in Madison County targeting aquifer 110QRNR, collecting 14 iron measurements from 11 separate wells between July 2011 and August 2023. These results show iron was detected in 13 samples, with values ranging from 4.3 to 3150 micrograms per liter (ug/L) and a median of 167 ug/L.
Importantly, none of the sampled iron concentrations exceeded federal drinking water thresholds. This means the data do not indicate any regulatory violation or defined health hazard related to iron content for this area. However, these readings reflect conditions observed in wells other than your own and cannot specify your household's water iron level.
Influence of Well Depth and Source Type on Iron Bacteria Presence
The sampled wells ranged from 17 to 102 feet deep, which is typical for residential, public, and agricultural groundwater sources in Madison County's 110QRNR aquifer. Iron concentrations and the likelihood of iron bacteria presence can vary widely with well depth as well as aquifer characteristics. Shallower wells sometimes show higher iron levels due to oxidation and exposure to surface influences, while deeper wells may have more stable but less predictable iron flora.
Since these samples cover a range of well depths, your own water conditions could differ depending on how deep your water source is and the local aquifer environment.
Consequences of Long-Term Untreated Iron Bacteria in Residential Water Systems
If iron bacteria go unaddressed over many years in household water supplies, deposits of slime and biofilm can accumulate. This can lead to clogged pipes, staining of fixtures and laundry, and unpleasant changes in water appearance or taste. Iron bacteria themselves are not a health risk, but their presence often signals iron levels that create operational nuisances indoors.
Distinguishing Aesthetic Secondary Standards from Health-Based Limits in Iron Management
Iron is regulated under aesthetic secondary standards rather than primary health-based limits. These secondary standards focus on taste, odor, color, and staining rather than safety. The U.S. EPA does not designate iron as a contaminant with a primary maximum contaminant level (MCL). Thus, iron detection—even above secondary thresholds—does not imply unsafe drinking water but indicates conditions that may affect your water’s look, smell, or plumbing system.
Interpreting the Madison County Iron Data as a Homeowner
The median iron concentration recorded in the samples is 167 ug/L, with some wells showing values as high as 3150 ug/L. If your well’s iron level is closer to the higher end, you may experience more pronounced staining and biofilm issues. Conversely, values near the lower range are less likely to cause noticeable effects.
To accurately assess your situation, a specific test on your household water is necessary. Only this will establish your water’s iron concentration and whether you should consider treatment.
Conclusion: Appropriate Cautions When Using Area Iron Data
The Madison County aquifer 110QRNR iron data provide useful context but should not define your water’s iron condition. These government-sampled measurements reflect a broad area’s groundwater quality and do not substitute for individual water testing.
If iron bacteria-related concerns exist in your household water, equipment such as the C-Series Iron Bacteria & Slime Filter ships ready to configure and is designed to address iron bacteria problems effectively. Consultation with a water professional and testing your well water will guide choosing the best approach for your needs.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2023-08-23. These figures describe groundwater sampled in this area. They are not a test of any individual private well - only a test of that well can establish its own water.
On record: U.S. Geological Survey sampling of Iron in the 110QRNR aquifer (Madison County): 14 results from 11 wells, median 167.0 ug/L, range 4.3-3150.0 ug/L; none above any federal threshold