Well water in Armstrong County, PA
What Penn State well tests show for Armstrong County, compared with Pennsylvania as a whole.
About 70% of the Armstrong County well samples Penn State tested were positive for coliform bacteria (statewide: 44%). Compared with the rest of Pennsylvania, it stands out for E. coli (23% vs. 11% statewide) and manganese (38% vs. 22% statewide).
What local well tests found
| Test (share of samples over the guideline) | Armstrong County | Pennsylvania |
|---|---|---|
| Total coliform bacteria | 70.2% | 44.1% |
| E. coli bacteria | 23.4% | 10.6% |
| Corrosivity (likely to eat pipes) | 70.6% | 65.9% |
| pH outside 6.5 to 8.5 | 16.0% | 16.6% |
| Manganese (stains) | 37.5% | 22.3% |
| Iron (stains) | 28.6% | 17.2% |
| Lead, first-draw sample | 6.5% | 8.9% |
| Arsenic | 0.0% | 5.5% |
| Nitrate | 0.0% | 4.1% |
| Typical hardness (median) | 5.9 gpg | 5.0 gpg |
Source: Penn State Agricultural Analytical Services Lab, Armstrong County summary (126 samples) and statewide summary (24,726 samples), tested 2007 to 2025. These are wells whose owners chose to test, often because of a problem, so rates may run higher than for all wells. Some tests had fewer samples than others.
Problems to watch for here
- Bacteria in your well
- Manganese (black stains)
- Iron (orange stains)
- Corrosive water and blue-green stains
What to do next
- Test, if you haven't in a year. See testing options and prices.
- Read your results. Use our results tool, or upload a photo of your report.
- Get a fair quote if something needs fixing.
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