How Well Depth and Source Affect Expected Iron Levels in Rockingham County
The groundwater samples reported by the U.S. Geological Survey come from bedrock wells ranging from 150 to 900 feet deep in Rockingham County. Because iron bacteria levels can vary notably with depth and source characteristics, homeowners should recognize that the area’s sampling reflects a broad range of well depths and not a single water source. For example, shallower wells commonly experience different iron bacterial activity than deep bedrock wells. This range means regional data offers context but cannot pinpoint conditions in any individual home’s supply.
Differences Between Public Water Records and Private Well Testing
Public water system records generally show comprehensive, regularly updated water quality results that often meet health-based standards. Private wells, common in Rockingham County’s bedrock-dominated areas, lack routine monitoring unless the owner tests specifically. The USGS groundwater sampling provides a snapshot across several wells but does not substitute for a homeowner’s own water analysis. Such individual testing is essential to understand unique iron bacteria presence and to identify the particular treatment needs within a home.
Secondary Standards for Aesthetics Versus Health-Based Limits for Iron
Iron in water has secondary standards, which focus on visual and taste effects rather than health risks. In Rockingham County, only 2 out of 133 USGS samples exceeded the secondary standard of 0.3 mg/L for iron, indicating occasional potential for water discoloration or staining. This standard is not a health-based limit and does not reflect safety concerns. Understanding this difference helps residents interpret area iron detections without assuming health hazards.
Sample Size and Its Impact on Data Reliability
The USGS data reflects 133 samples collected from 27 distinct wells over eight years. This sample size provides a substantial overview of iron presence across the Rockingham County bedrock aquifer, but the variability from well to well and over time is notable. Smaller datasets might miss such variation, while this larger sample helps identify the typical iron concentrations and extremes encountered in the area. Homeowners should note that individual wells could still differ widely from these medians and ranges.
Comparing Rockingham County’s Iron Data with Neighboring Counties
When comparing Rockingham County’s iron bacteria data to neighboring counties, it is important not to overinterpret differences. Variations in geology, well depth, and sampling periods can affect median and range values. Each county’s data reflects local conditions and sampling methods, so regional comparisons serve best to understand broader trends rather than predict a home’s water quality directly. Homeowners should always rely on direct testing for their property’s water.
Interpreting 'Detected', 'Median', and 'Range' in Rockingham County’s Sampling Record
In the USGS record, iron was detected in 114 out of 133 samples, but detection only means the presence was measurable, not that levels are problematic. The median iron concentration was 64.95 micrograms per liter—well below the secondary aesthetic standard—and the range extended up to 8,530 micrograms per liter in some wells. This wide range underscores that individual water can vary dramatically. Median values provide a central tendency but do not define a home’s water without specific testing.
What Rockingham County’s Iron Bacteria Data Does Not Establish
Area water quality data cannot substitute for personal well testing; it does not identify if your home experiences iron bacteria issues or their severity. Detection does not imply safety concerns or violations. The occasional exceedance of aesthetic secondary standards merely suggests potential taste or staining effects in some wells. For residential water challenges with iron bacteria, the Pentair Iron Bacteria & Slime Filter ships ready to configure and effectively manages these constituents once you know your water’s specific condition.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2019-08-21. 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 BEDROCK aquifer (Rockingham County): 133 results from 27 wells, median 64.95 ug/L, range 0.0-8530.0 ug/L; 2 above an AESTHETIC secondary standard only (secondary standard 0.3 mg/L (aesthetic)) - not a health finding