What does the measured range of calcium and magnesium in Androscoggin County bedrock groundwater mean compared to federal standards?
Groundwater samples from three deep wells in the bedrock aquifer of Androscoggin County, taken between August and October 2011, showed calcium and magnesium concentrations with a median of 64.7 mg/L, ranging from 54.5 to 89.3 mg/L. None of these samples exceeded any federal health-based thresholds. It's important to understand that detection of these minerals at these levels does not indicate a safety violation or health risk, but rather reflects typical water composition in this aquifer.
How would a homeowner interpret the median and range from this water quality record?
A homeowner considering these figures might expect their water to contain moderate levels of calcium and magnesium, which contribute to water "hardness." This hardness can cause dryness in skin by reducing water’s ability to rinse away residues and by interacting with soaps. The range shows natural variability in water quality across different wells within the county's bedrock aquifer, so individual household water could be somewhat softer or harder. Testing one’s own water is necessary to confirm precise hardness levels.
How can I compare Androscoggin County’s bedrock water quality data with that from neighboring counties without overinterpreting the differences?
While counties adjacent to Androscoggin may show varying concentrations of calcium and magnesium due to different aquifer characteristics, these variations do not necessarily imply better or worse water for skin-related concerns. Differences in geology, well depth, and sampling times can affect results. Therefore, comparing area medians provides general context, but individual water tests remain essential for personal decisions.
Why do aesthetic secondary standards differ from health-based limits for calcium and magnesium in water?
Calcium and magnesium in water primarily affect aesthetic qualities such as taste, soap interaction, and potential for mineral deposits, rather than posing direct health risks. Federal secondary standards focus on factors like staining or taste, not health safety. Thus, exceeding an aesthetic threshold for hardness does not mean the water is unsafe; it only signals that some users might notice effects like dry skin or scale buildup.
How do calcium and magnesium enter groundwater in the Androscoggin County bedrock aquifer?
Calcium and magnesium naturally dissolve into groundwater as it flows through rock formations rich in minerals like limestone and dolomite common to Androscoggin County’s bedrock. The depth of sampled wells—between 262 and 304 feet—indicates these minerals have been picked up over prolonged contact with these geological formations. Understanding this natural process helps explain why hardness varies across wells.
What should I NOT conclude from this area-wide water data about my household’s dry skin?
Area sampling data offers valuable insight but cannot pinpoint individual well conditions or confirm that bedrock water hardness causes dry skin in your home. Personal water testing is necessary to identify specific mineral levels and confirm if they contribute to skin dryness. For households considering treatment options, the Autotrol Dry, Itchy Skin System ships ready to configure and is designed to address hardness-related skin effects by conditioning water to reduce mineral impact. However, selecting this system should follow testing and understanding your own water quality rather than relying solely on area medians.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2011-10-13. 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 Hardness, Ca, Mg in the BEDROCK aquifer (Androscoggin County): 3 results from 3 wells, median 64.7 mg/L, range 54.5-89.3 mg/L; none above any federal threshold