Arsenic in Pennsylvania well water
In Pennsylvania, 5% of 5,555 private wells tested between 2007 and 2025 had arsenic above the EPA limit (10 ug/L), according to the Penn State water testing lab.
Arsenic occurs naturally in New England bedrock and dissolves into well water. Long-term exposure raises the risk of bladder, lung and skin cancers, and is linked to heart disease and lower IQ in children. It has no taste or smell, so testing is the only way to know.
Check your arsenic number
Type the value from your lab report. It is compared to the EPA limit and the EPA limit, the same way the full interpretation does it.
Test your Pennsylvania well for arsenic
Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.
Order the Tap Score well water test kit, from $209Already tested? Upload the report
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Systems that remove arsenic
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Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.
For arsenic
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
For arsenic
Whole-house arsenic and uranium filter
whole-house, at the point of entry, about $2,500
Adsorptive iron-based media; sized to your well yield.
For arsenic
Aquasana SmartFlow reverse osmosis
under-sink or countertop, about $225
Certified to NSF/ANSI 58 and 53 to reduce arsenic (96%, pentavalent), fluoride (90%), lead (99%), nitrate, nitrite and PFOA/PFOS at the kitchen tap, with a remineralizer.
Rather have it installed and sized for your well? Book a free in-home water test with a licensed local company.
Where to get a well tested for arsenic in Pennsylvania: certified labs, state programs and prices.
By county, from homeowner tests
Share of private wells above the state guidance level (10 ug/L) in tests homeowners sent to the state lab, 2008 to 2025.
| County | Above state level | Wells tested | Highest |
|---|---|---|---|
| Crawford | 41 | 65 ug/L | |
| Perry | 100 | 39 ug/L | |
| Mifflin | 35 | 42 ug/L | |
| Juniata | 30 | 18 ug/L | |
| Huntingdon | 83 | 48 ug/L | |
| Wyoming | 63 | 57 ug/L | |
| Lycoming | 79 | 62 ug/L | |
| Erie | 78 | 27 ug/L | |
| Clinton | 72 | 38 ug/L | |
| Montgomery | 162 | 109 ug/L | |
| Wayne | 209 | 80 ug/L | |
| Bedford | 53 | 73 ug/L | |
| Bradford | 69 | 141 ug/L | |
| Adams | 59 | 33 ug/L | |
| Schuylkill | 36 | 24 ug/L |
By county, from individual samples
Public monitoring samples against the EPA limit (10 ug/L); counties with at least 30 samples.
| County | Above EPA limit | Samples | Detected | Median | Highest |
|---|---|---|---|---|---|
| Clarion | 758 | 44% | 0 | 1,000 ug/L | |
| Erie | 87 | 37% | 0 | 505 ug/L | |
| Montgomery | 84 | 73% | 2 | 31 ug/L | |
| Philadelphia | 91 | 35% | 0 | 50 ug/L | |
| Bucks | 135 | 70% | 1.5 | 54 ug/L | |
| Tioga | 200 | 40% | 0 | 56.8 ug/L | |
| Dauphin | 78 | 88% | 1.05 | 48 ug/L | |
| Susquehanna | 56 | 70% | 0.535 | 28 ug/L | |
| Berks | 85 | 56% | 0.3 | 58 ug/L | |
| Lycoming | 128 | 66% | 0.45 | 23.6 ug/L | |
| Snyder | 33 | 88% | 1 | 17 ug/L | |
| Bradford | 246 | 61% | 0.46 | 178 ug/L | |
| Wayne | 259 | 82% | 0.39 | 188 ug/L | |
| Wyoming | 38 | 66% | 1.7 | 13 ug/L | |
| Centre | 94 | 21% | 0 | 28 ug/L |
- Monroe township, Clarion County71% of 169
- Piney township, Clarion County26% of 582
- Philadelphia, Philadelphia County11% of 91
- Lackawaxen township, Pike County9% of 64
- West Burlington township, Bradford County2% of 42
- Myerstown borough, Lebanon County0% of 48
- Upper Mahanoy township, Northumberland County0% of 105
- Dingman township, Pike County0% of 55
- Letterkenny township, Franklin County0% of 159
- Shippen township, Tioga County0% of 40
- Greene township, Pike County0% of 32
- Marshall township, Allegheny County0% of 42
- Ulysses township, Potter County0% of 51
- Green township, Indiana County0% of 30
- New Garden township, Chester County0% of 83
- Kidder township, Carbon County0% of 47
- West Lampeter township, Lancaster County0% of 151
- Boggs township, Clearfield County0% of 436
Sources
- Penn State Agricultural Analytical Services Lab drinking water summaries: County summaries of private water samples tested by the Penn State Agricultural Analytical Services Laboratory since 2007, published by the College of Agricultural Sciences. Counts are samples, not distinct wells. Shares are against the standard the lab prints: the EPA maximum contaminant level, or the secondary standard for iron, manganese and chloride. Lead is the first-draw result. Medians printed as 0.00 are stored as null because the lab rounds to two decimals. Retrieved September 16, 2026.
- Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. arsenic counts and shares are listed on each county and town page with their sources.
Analysis: Arsenic in private wells, state by state, from the same public records.