Well water in Lancaster County, Pennsylvania

1in2

Testing strongly recommended

tested well samples in Lancaster County exceeded the EPA limit for nitrate (10 mg/L), based on public data from USGS Water Quality Portal.

532 private wells tested 2007 to 2025 in state summaries; 9,087 test results across 13 contaminants from at least 615 wells, 1925 to 2022; nitrate has the most at 4,942. Data refreshed September 16, 2026.

Compiled by Nick at Well Water Nerd from public records. How these pages are built

These are samples homeowners paid to send to the Penn State lab, often because of a suspected problem, so shares above the limit run higher than a random survey would find.

An estimated 237,606 people in Lancaster County get their drinking water from a private well, per USGS 2015 county water use. That is about 44% of residents.

Separately, the USGS national arsenic model estimates that 2% of the 237,606 people on private wells in Lancaster County draw water above 10 ug/L (the model's range is 1% to 2%), from geology and well depth rather than local tests.

What homeowner tests found

Penn State Agricultural Analytical Services Lab drinking water summaries: private wells tested and reported to the state, 2007 to 2025. Shares are against the level the state applies to each contaminant, named in the last column; several are stricter than EPA.

Contaminant	Above state level	Wells tested	Median	Highest	State level
Total coliform	42%	532		257	0 MPN/100mL
Nitrate + nitrite as N	25%	403	5.8	30.1	10 mg/L
Manganese	15%	109	10	2,930	50 ug/L
Lead (first draw)	12%	149		121	15 ug/L
E. coli	10%	532		201	0 MPN/100mL
Iron	9%	115	100	4,000	300 ug/L
Arsenic	<1%	122		51	10 ug/L
Copper	<1%	181	0.01	1.95	1.3 mg/L
Chloride	0%	26	28.6	93.9	250 mg/L
Sodium		32	18.8	188

What individual samples found

Each row summarizes every public sample for that contaminant inside Lancaster County. Above limit means above the EPA maximum contaminant level; where EPA has no enforceable limit, the row shows a health guideline or nuisance level instead.

Contaminant	Above limit	Samples	Detected	Median	Highest	Limit
Nitrate 1925 to 2022	62%	4,942	98%	12	443	10 mg/L EPA limit
Radium (226 + 228) 1986 to 2022	23%	104	85%	1.4	110	5 pCi/L EPA limit
E. coli 1994 to 2022	7%	42	7%	0	10	0 MPN/100mL EPA limit
Fluoride 1961 to 2022	0%	534	81%	0.1	1.3	4 mg/L EPA limit
Arsenic 1976 to 2022	0%	245	22%	0	7	10 ug/L EPA limit
Uranium 1986 to 2022	0%	238	84%	5	19	30 ug/L EPA limit
Lead 1976 to 2022	0%	237	47%	0	10	15 ug/L EPA limit
Copper 1976 to 2022	0%	163	21%	0	0.16	1.3 mg/L EPA limit
Chloride 1925 to 2022	no limit	874	100%	24	545	250 mg/L nuisance level
Sodium 1925 to 2022	no limit	664	100%	7.99	240	20 mg/L health guideline
Iron 1925 to 2022	no limit	446	67%	34	80,000	300 ug/L nuisance level
Manganese 1961 to 2022	no limit	428	89%	20	4,180	300 ug/L health guideline
Radon 1986 to 2021	no limit	170	98%	1,200	38,000	2,000 pCi/L health guideline

Over time

Share of samples above the limit by period. A cell needs ten samples to show; a comparison needs twenty in each period. Later periods sample fewer wells, and often the ones already known to have a problem.

Contaminant	before 2000	2000s	2010s	2020s
Nitrate	66%3,927 samples	53%468 samples	43%521 samples	31%26 samples
Fluoride	0%267 samples	n/a	0%261 samples	n/a
Arsenic	0%79 samples	n/a	0%152 samples	0%13 samples
Uranium	0%80 samples	n/a	0%152 samples	n/a
Lead	0%79 samples	n/a	0%152 samples	n/a

Nitrate above the limit in Lancaster County fell from 43% of 521 samples in the 2010s to 31% of 26 in the 2020s.

Fluoride, arsenic, uranium, lead have held within a few points between the two most recent periods with enough samples.

Closer than the county

See the sampled wells near your address

The same records, drawn around one point: which wells within a few miles were sampled and what they found, how deep the wells next to you were drilled, and any leaking tank or cleanup site within a mile.

Check my address

What this means

Among homeowners in Lancaster County who sent a sample to the state lab, the health-based limits most often exceeded were total coliform (42% of 532 wells), nitrate (25% of 403 wells), and lead (12% of 149 wells). These are ordinary wells tested by their owners, so the shares are the best available picture of a typical well here, with one caveat: people test more often when they suspect a problem.

Manganese exceeds the state's advisory level in a sizable share of wells; this is mostly a taste, staining or diet issue rather than a toxicity one.

What to test for in Lancaster County

1
Nitrate
62% of 4,942 local samples were above the limit.
2
Total coliform
42% of 532 local wells tested were above the EPA limit.
3
Radium (226 + 228)
23% of 104 local samples were above the limit.
4
Lead
12% of 149 local wells tested were above the EPA limit.
5
E. coli
10% of 532 local wells tested were above the EPA limit.
6
Arsenic
<1% of 122 local wells tested were above the EPA limit.
7
Copper
<1% of 181 local wells tested were above the EPA limit.
8
Radon
Median local reading is 1,200 pCi/L.

Test your Lancaster County well for nitrate, total coliform and radium (226 + 228)

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 $209 Already tested? Upload the report

Just want bacteria checked first? Tap Score coliform and E. coli test, $99. Coliform and E. coli are the tests every well needs every year.

Want a quick look before paying for a lab? Home well water test strips on Amazon check hardness, iron, pH and nitrate in minutes. They are a screen, not a result: arsenic, bacteria, uranium and PFAS need a certified lab.

Affiliate links: the merchant pays us a commission and the price is the same for you. It does not change what the data above says. As an Amazon Associate we earn from qualifying purchases.

Where to get a well tested in Pennsylvania: certified labs, state programs and prices.

Already have results back? Get your lab report read against the Lancaster County numbers, $29. Every line explained, ranked by what matters, with the fix for each.

Wells in Lancaster County

14,953 domestic wells in Lancaster County are on record with the state. 99% are drilled into bedrock, and the typical well is 200 feet deep (one in ten goes past 450 feet).

In a typical Lancaster County well, bedrock starts about 30 feet down, the median yield is 10 gallons per minute, 17% of wells yield under 3 gallons per minute and usually need a storage tank.

Bedrock wells are where arsenic, uranium and radon come from: the water sits in fractures in granite and metamorphic rock and picks up whatever the rock carries. That is why testing for those three matters more here than in a dug or gravel well.

Find your own well's report

The state keeps the driller's report for most wells drilled since 1984. It tells you how deep your well is, where bedrock starts, and how much water it makes, which decides what treatment can work.

Open PaGWIS (Pennsylvania Geological Survey) and choose Water Well.
The record lists depth, depth to bedrock, yield and use; drillers have reported new wells to the state since 1966.

Pennsylvania has no private well construction standard and does not require testing, so many older wells have no record at all.

The rock under Lancaster County

Piedmont and Blue Ridge carbonate-rock aquifers

Carbonate-rock. Limestone and dolomite move water through cracks and solution channels, sometimes very fast. Bacteria and nitrate can travel from the surface to a well in days, so annual bacteria testing matters more here than most places; hardness is a given.

Classification from the USGS Principal Aquifers of the United States (national map, 2003 edition, GIS release 2015), read at the county centroid. A single well can sit in a different unit, especially near a boundary.

Official help in Pennsylvania

Two places to start that are not selling anything: the state program that answers private well questions, and its list of labs certified to run drinking water tests. A certified lab is the difference between a result you can act on and a number.

Private Wells, PA DEP
Laboratory Accreditation Program, PA DEP

Treatment that fits the local profile

Total coliform

Inspect and repair the well cap and casing, then shock chlorinate and retest; UV disinfection whole-house; Chlorination system

Nitrate

Point-of-use reverse osmosis; Anion exchange; Distillation

Lead

Point-of-use reverse osmosis; Certified lead-removal carbon filter; Neutralizing filter to raise pH and stop leaching

E. coli

Shock chlorination and fix the well cap or casing; UV disinfection whole-house; Chlorination system

Manganese

Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis

Radium (226 + 228)

Water softener (cation exchange); Point-of-use reverse osmosis

Systems we would look at first

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 total coliform

Aquasana Rhino Well Water with UV

whole-house, at the point of entry, about $2,871

Whole-house system built for wells: sediment pre-filter, KDF and carbon, and a UV lamp rated to kill 99.99% of bacteria and viruses. It does not remove arsenic, nitrate, uranium or radon.

For nitrate

Under-sink reverse osmosis system

under-sink or countertop, about $300

Look for NSF/ANSI 58 certification listing the contaminant you need removed.

For nitrate

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.

For lead

Aquasana Claryum 3-Stage under-sink filter

under-sink or countertop, about $175

Certified to NSF/ANSI 53 to reduce 99% of lead and 99.7% of PFOA and PFOS at the tap. Not a fix for arsenic, nitrate or bacteria.

For lead

Acid neutralizing filter

whole-house, at the point of entry, about $1,200

Raises pH so plumbing stops leaching lead and copper.

For E. coli

UV disinfection system

whole-house, at the point of entry, about $900

Fix the well cap and casing first; UV keeps bacteria from returning.

Free, no obligation

Get on the list for a free in-home water test in Lancaster County

No water treatment company serves Lancaster County through Well Water Nerd yet. We are signing licensed companies on county by county: they test at your tap for free, walk you through the numbers, and quote treatment only if something needs fixing. Leave your details and you are first in line. Nothing is shared until a company joins for Lancaster County, and you get an email naming it first.

Common questions

How deep are wells in Lancaster County?

The typical domestic well in Lancaster County is 200 feet deep, based on 14,953 wells reported to the state. One in ten is deeper than 450 feet. 99% are drilled into bedrock.

Is there arsenic in well water in Lancaster County?

Arsenic was detected in 22% of 245 public well samples in Lancaster County, and 0% were above the EPA limit of 10 ug/L. Arsenic has no taste or smell; a lab test is the only way to know your level.

How high is radon in well water in Lancaster County?

The median radon level across 170 public samples in Lancaster County was 1,200 pCi/L, with a high of 38,000 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.

How often should I test a private well in Lancaster County?

Test for bacteria and nitrate every year. Test once for arsenic, uranium, radon, fluoride, manganese and PFAS, then again every three to five years or after any change in taste, color, or plumbing.

Towns in Lancaster County

47 towns have fewer than 30 public samples and are included in the Lancaster County totals above rather than shown separately: Adamstown borough, Akron borough, Bart township, Christiana borough, Clay township, Colerain township, Columbia borough, Conestoga township, Conoy township, Denver borough, Drumore township, East Cocalico township, East Donegal township, East Drumore township, East Hempfield township, East Petersburg borough, Eden township, Elizabethtown borough, Elizabeth township, Ephrata borough, Fulton township, Lancaster, Lancaster township, Lititz borough, Little Britain township, Manheim borough, Manheim township, Manor township, Marietta borough, Martic township, Millersville borough, Mount Joy borough, Mount Joy township, Mountville borough, New Holland borough, Penn township, Pequea township, Quarryville borough, Rapho township, Sadsbury township, Strasburg borough, Terre Hill borough, Warwick township, West Cocalico township, West Donegal township, West Earl township, West Hempfield township.

Counties near Lancaster County

Closest first. Groundwater does not stop at a line on a map, so the next county over is a fair second opinion.

Want the numbers themselves? Download the Pennsylvania dataset as CSV, every county and town, with the sources named.

Sources

USGS Water Quality Portal: 9,087 samples in Lancaster County. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
Penn State Agricultural Analytical Services Lab drinking water summaries: summaries for 10 contaminants in Lancaster County, up to 532 wells each. 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.
USGS national arsenic model (Ayotte 2017): estimated share of 237,606 people on private wells in Lancaster County above 10 ug/L of arsenic, from geology, well depth and land use. County estimates of domestic well users with arsenic above 10 ug/L from the USGS national logistic regression model (Ayotte, Medalie and Qi, 2017), with private well population from the USGS 2015 county water-use compilation (Dieter and others, 2018). Retrieved September 15, 2026.
Pennsylvania Groundwater Information System (PaGWIS) wells: 24,861 well records in Lancaster County, 14,953 domestic. Water well records from the Pennsylvania Groundwater Information System, Pennsylvania Geological Survey (DCNR). Only aggregates are shown; owner names and addresses are never stored. Retrieved September 16, 2026.

Non-detects count as samples and are treated as zero when computing medians. Exactly at the limit counts as not above it. A sample belongs to the town containing the well's reported coordinates.