Well Water Notebook
Information only, not medical advice. We never say whether your water is safe to drink. Ask a state-certified lab or your local health department. Disclaimer

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Well water testing in Lancaster County, Pennsylvania

Lancaster County has more people on private wells than any other Pennsylvania county in the USGS data, and the Penn State lab data show nitrate and bacteria as the most common problems. Here's what the data show, what Pennsylvania recommends, and where to get a sample analyzed, with a source for every fact.

This page can't tell you whether your water is safe to drink. Only a test of your well can do that. For help, contact a DEP-accredited lab or the DEP office below.

How many people here use a private well

USGS estimates that about 238,000 people in Lancaster County supplied their own household water in 2015, about 44% 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 Lancaster 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 Lancaster County, the summary covers 555 samples from 8/15/2007 - 6/16/2025:3

Test Counted as failing Samples failing Percent
Total coliform bacteria present (standard: 0) 221 of 532 41.5%
E. coli bacteria present (standard: 0) 55 of 532 10.3%
Nitrate + nitrite (as N) over 10 mg/L 100 of 403 24.8%
pH (secondary standard) outside 6.5–8.5 86 of 485 17.7%
Iron (secondary standard) over 0.3 mg/L 10 of 115 8.7%
Manganese (secondary standard) over 0.05 mg/L 16 of 109 14.7%
Lead, first draw over 0.015 mg/L 18 of 149 12.1%
Arsenic over 0.01 mg/L 1 of 122 0.8%

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 3,700 domestic-well users in Lancaster County (95% confidence range about 2,700–5,100, 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

Bacteria test kits: DEP says bacterial test kits can be bought from its regional offices. For Lancaster County, that's DEP's Reading District Office (serving Berks and Lancaster counties): 610-916-0100.6

Accredited labs: DEP publishes lists of labs certified for chemical testing and bacteriological testing (PDFs dated June 2024).6 The Penn State AASL also offers drinking water test packages for well and spring owners.2

The Chester County Health Department's list of well water testing labs includes these in Lancaster County:7

Lab Address Phone
Eurofins Lancaster Laboratories Environmental, Inc. 2425 New Holland Pike, Lancaster 717-656-2300
Owl Hill Laboratories 9 Cindy Circle, Lititz 717-627-2520

Confirm with any lab that it's accredited for each test you need.

If a result is high: DEP says that if results are higher than Pennsylvania's MCLs, you should install a treatment device for that specific contaminant, and it points to NSF's treatment resources and certified product database.6 Our guides cover what agencies say works:

  1. 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 ↩

  2. 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 ↩↩↩↩↩

  3. Penn State Agricultural Analytical Services Laboratory, "Summary of Drinking Water Samples Tested: Lancaster County." https://agsci.psu.edu/aasl/water-testing/drinking-water-testing/drinking-water-test-summaries/lancaster ↩

  4. U.S. EPA, "Secondary Drinking Water Standards: Guidance for Nuisance Chemicals." https://www.epa.gov/sdwa/secondary-drinking-water-standards-guidance-nuisance-chemicals ↩

  5. 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 ↩

  6. Pennsylvania DEP, "Private Wells: Water Testing." https://www.pa.gov/agencies/dep/residents/my-water/private-wells/water-testing ↩↩↩↩

  7. Chester County Health Department, "Well Water Testing Labs in Chester County." https://www.chesco.org/978/Well-Water-Test-Labs ↩