Government sampling in Merrimack County's aquifer 112SRFD shows copper was detected in all sampled wells, with a median concentration of 10.25 micrograms per liter (ug/L) and a range from 2.6 to 24.5 ug/L. No sample exceeded federal health thresholds.
How Are Copper Stains Different from Other Common Water Issues?
Copper stains form when dissolved copper in water deposits on plumbing surfaces and fixtures, creating blue-green discoloration. This contrasts with problems like iron staining, which typically produces reddish or brown marks, or hard water scale, which is white and chalky. Copper stains often show up on sinks, tubs, or around faucets and may indicate copper presence in the water but not necessarily a health concern.
What Do Terms Like 'Detected,' 'Median,' and 'Range' Mean in the Sampling Data?
'Detected' means copper was measured in all six samples; it is present but at levels below any federal threshold. 'Median' indicates the middle concentration when results are ordered, here 10.25 ug/L, showing typical local levels. 'Range' from 2.6 to 24.5 ug/L shows variability among wells but does not imply any sample exceeded safety limits.
What Does a Certified Laboratory Report for Copper Tell Me and How Should I Interpret It?
A certified laboratory report will state the copper concentration in your specific water sample, usually in micrograms per liter or parts per billion. It will confirm presence and quantity but does not determine if copper causes staining directly. Compare your result to area data and federal guidelines to assess if treatment consideration is warranted.
What Information Should I Record Before Seeking Treatment Advice?
- Your water source type (e.g., private well)
- Date and depth of sample
- Copper concentration from a certified test
- Visible signs of copper stains on fixtures or appliances
- Other water quality data you may have
How Should I Understand the Median and Range Figures as a Homeowner?
Seeing a median of 10.25 ug/L means half the sampled wells had copper levels at or below this figure. The highest reading at 24.5 ug/L remains below federal safety thresholds, suggesting copper is typically low but present. If your water test shows significantly higher levels, it may influence treatment needs.
How Do Public System Records Differ from Private Well Testing in What They Establish?
Public system records summarize sampling across a broad area and indicate regional water quality trends, not your tap’s exact composition. Private well testing provides a precise snapshot of your water. Both data types are important; area data guides expectations, but decisions should rely on your own test results.
For households in Merrimack County concerned about copper stains, the Autotrol Blue-Green Copper Stains Filter ships ready to configure and is designed to reduce copper-related discoloration by addressing the copper concentrations typical in this aquifer. Considering your certified lab results alongside local data will help you choose the right level of treatment for your home.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2019-10-08. 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 Copper in the 112SRFD aquifer (Merrimack County): 6 results from 3 wells, median 10.25 ug/L, range 2.6-24.5 ug/L; none above any federal threshold