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Well water testing in Berks County, Pennsylvania
In the Penn State lab data for Berks County, about 40% of samples had coliform bacteria, and arsenic failed more often (6.5% of samples) than in the Lancaster or Chester county summaries. Here's what the data show, what Pennsylvania recommends, and where to get a sample analyzed, with a source for every fact.
How many people here use a private well
USGS estimates that about 153,000 people in Berks County supplied their own household water in 2015, about 37% of the county's population.1 Statewide, Penn State Extension says over one million rural homes and farms use a private well or spring.2
Does Pennsylvania require testing?
No. Penn State Extension says there are no statewide regulations requiring testing of private wells and springs. Testing is the homeowner's voluntary responsibility.2
What tests in Berks County have found
The Penn State Agricultural Analytical Services Laboratory (AASL) publishes a summary of drinking water samples it has tested from each county. For Berks County, the summary covers 464 samples from 9/12/2007 - 6/16/2025:3
| Test | Counted as failing | Samples failing | Percent |
|---|---|---|---|
| Total coliform bacteria | present (standard: 0) | 175 of 435 | 40.2% |
| E. coli bacteria | present (standard: 0) | 34 of 435 | 7.8% |
| Nitrate + nitrite (as N) | over 10 mg/L | 15 of 200 | 7.5% |
| pH (secondary standard) | outside 6.5–8.5 | 74 of 399 | 18.5% |
| Iron (secondary standard) | over 0.3 mg/L | 20 of 184 | 10.9% |
| Manganese (secondary standard) | over 0.05 mg/L | 24 of 179 | 13.4% |
| Lead, first draw | over 0.015 mg/L | 12 of 146 | 8.2% |
| Arsenic | over 0.01 mg/L | 7 of 108 | 6.5% |
These are samples homeowners chose to send to one lab, not a random survey. Penn State presents the summaries as a guide to which problems are most common locally, to help you decide what to test.2 Iron, manganese and pH have secondary (aesthetic) standards, not health-based limits.4
A USGS national model estimates that about 2,800 domestic-well users in Berks County (95% confidence range about 2,000–4,200, based on 2010 population) have well water with predicted arsenic above 10 µg/L.5 That's a model estimate and can't predict any single well.
What to test and how often
PA DEP recommends testing your well every year for total coliform bacteria, nitrates, total dissolved solids and pH, plus anything else you suspect, using a state-certified lab.6 Penn State's county summaries are meant to help you decide what else to add.2
Where to get tested and treatment options
Related guides
- How to read your well water test results
- How often to test a private well
- Lancaster County, PA · Chester County, PA · York County, PA · All Pennsylvania county pages
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Dieter, C.A., and others, 2018, Estimated Use of Water in the United States County-Level Data for 2015 (ver. 2.0), U.S. Geological Survey data release (domestic self-supplied population). https://doi.org/10.5066/F7TB15V5 ↩
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Penn State Extension, "County Summaries of Pennsylvania Groundwater Well and Spring Data" (updated September 28, 2026). https://extension.psu.edu/county-summaries-of-pennsylvania-groundwater-well-and-spring-data ↩↩↩↩↩
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Penn State Agricultural Analytical Services Laboratory, "Summary of Drinking Water Samples Tested: Berks County." https://agsci.psu.edu/aasl/water-testing/drinking-water-testing/drinking-water-test-summaries/berks ↩
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U.S. EPA, "Secondary Drinking Water Standards: Guidance for Nuisance Chemicals." https://www.epa.gov/sdwa/secondary-drinking-water-standards-guidance-nuisance-chemicals ↩
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Ayotte, J.D., Medalie, L., and Qi, S.L., 2017, Estimated county level domestic well population with arsenic greater than 10 micrograms per liter based on probability estimates for the conterminous U.S., U.S. Geological Survey data release. https://doi.org/10.5066/F7CN724V ↩
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Pennsylvania DEP, "Private Wells: Water Testing." https://www.pa.gov/agencies/dep/residents/my-water/private-wells/water-testing ↩↩↩↩
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Chester County Health Department, "Well Water Testing Labs in Chester County." https://www.chesco.org/978/Well-Water-Test-Labs ↩