Well water in Dauphin County, PA
What Penn State well tests show for Dauphin County, compared with Pennsylvania as a whole.
In short
About 40% of the Dauphin County well samples Penn State tested were positive for coliform bacteria (statewide: 44%). Other results are close to or below the statewide averages, but bacteria and corrosive water are still worth testing for.
What local well tests found
40%failed for coliform bacteria
69%were corrosive to plumbing
20%had manganese over the stain level
| Test (share of samples over the guideline) | Dauphin County | Pennsylvania |
|---|---|---|
| Total coliform bacteria | 40.5% | 44.1% |
| E. coli bacteria | 6.5% | 10.6% |
| Corrosivity (likely to eat pipes) | 69.4% | 65.9% |
| pH outside 6.5 to 8.5 | 14.5% | 16.6% |
| Manganese (stains) | 19.6% | 22.3% |
| Iron (stains) | 16.0% | 17.2% |
| Lead, first-draw sample | 10.1% | 8.9% |
| Arsenic | 6.7% | 5.5% |
| Nitrate | 2.8% | 4.1% |
| Typical hardness (median) | 5.1 gpg | 5.0 gpg |
Source: Penn State Agricultural Analytical Services Lab, Dauphin County summary (353 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
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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