Well water testing in Chester County, Pennsylvania (2026)
Chester County has an estimated 70,000 households on private wells by EPA’s 2020 model, one of the largest counts in the country. The county Health Department regulates new wells, but it doesn’t run a homeowner lab or sell a kit. It points you to a list of certified labs. Here are the two on that list that sit inside the county, the cheapest posted statewide option, and what Chester County’s rocks say you should add.
The short version
- Test every year, in the spring. That’s the Chester County Health Department’s advice. The yearly panel PA DEP recommends is coliform bacteria, nitrate, total dissolved solids, and pH.
- The cheapest posted price is Penn State’s lab. Its Agriculture/Septic package (bacteria, E. coli, pH, TDS, and nitrate) is $70 by mail. Bacteria has to arrive within 30 hours, and never on a Friday.
- Want to drop a bottle off locally? Two DEP-accredited labs on the county’s list are in Chester County: Brandywine Science Center in Kennett Square (610-444-9850) and H.O. Thompson Testing Lab in Parkesburg (610-593-5030). Neither posts prices online, so call.
- Chester County’s rocks call for a few more tests. Radon in well water is common here, and some wells run high on arsenic, uranium, or nitrate. Water is often acidic. If you live near a known solvent site like Bishop Tube in East Whiteland, also test VOCs and PFAS.
Chester County Health Department: what it does and doesn’t do
The Chester County Health Department (CCHD) runs the county’s wells and well water testing program. It permits and approves new wells. It does not test homeowner samples. Instead it keeps a list of well water test labs for Chester County residents. Every lab on it is PA DEP-certified, and many are outside the county. On its well water page, CCHD recommends testing your well every year, in the spring.
CCHD: 601 Westtown Rd., Suite 295, West Chester, PA 19380 · 610-344-6225 · cchd@chesco.org. For water quality questions, its well pages give 610-344-6526. If a result comes back high, call them before you call a treatment company.
DEP-accredited labs in Chester County
These two labs are on CCHD’s list. Both also appear on PA DEP’s accredited-lab reports, the June 2024 lists linked from DEP’s private-well testing page. Neither posts homeowner prices, so call for a quote. Neither sells treatment equipment as far as we could find.
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| Lab | DEP-accredited for (drinking water) | Price | Notes |
|---|---|---|---|
| Brandywine Science Center (BSC Labs) 204 Line Rd., Kennett Square, PA 19348 610-444-9850 | Lab ID 15-00301: total coliform and E. coli, nitrate and nitrite, lead, copper, pH, alkalinity, TDS, sulfate, turbidity | Not posted. Call. | Serves private water supplies and real estate. Posted hours 9:00 a.m.–5:00 p.m. Its sampling page says to get the bottle to the lab within 2 hours, on ice if the drive is more than 15 minutes. It sells no treatment; its own site tells you to send your report to at least three treatment companies and compare. Arsenic isn’t on its DEP drinking water list, so ask before you order it there. |
| H.O. Thompson Testing Lab 104 Valley View Dr., Parkesburg, PA 19365 610-593-5030 or 800-373-5029 | Lab ID 15-00346: total coliform and E. coli | Not posted. Call. | Focuses on home buyers and sellers, offers sample pickup, and also tests radon. Its website didn’t load for us tonight, so call to confirm what it runs. For nitrate or metals, use a lab accredited for them. |
Other labs on the county’s list are in Berks, Bucks, Delaware, Lancaster and other counties. For any analyte, you can check a lab in DEP’s accredited-lab search. We only list labs we could verify, and we skip anyone who sells water treatment.
Penn State’s lab, the cheapest posted option
Penn State’s Agricultural Analytical Services Lab (AASL) is DEP-accredited and sells homeowner kits by mail and through county Extension offices. Its listed prices on October 22, 2026:
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| Package | What’s in it | Price |
|---|---|---|
| WD01 Standard | Total coliform, E. coli, pH, TDS | $60 |
| WD04 Agriculture / Septic | Standard plus nitrate-nitrogen. A good fit for the yearly Chester County test. | $70 |
| WD08 Extensive | Adds hardness, corrosivity, arsenic, lead, copper, iron, manganese, sodium, chloride, sulfate, nitrate and more | $220 |
| Arsenic only | Add-on | $30 |
The catches: bacteria must reach the lab within 30 hours of sampling, the lab won’t accept bacteria samples on a Friday, and results take about 10–14 business days. AASL doesn’t do chain of custody, so it isn’t the right lab for most home sales.
There are two more state options. DEP’s Southeast Regional Office sells bacterial test kits for Chester County (John Cairnes, 484-250-5106). And the PA Department of Health works with Penn State Extension on limited free private-well testing. Ask what’s open at dehe@pa.gov or 717-787-3350.
What’s in Chester County groundwater
Radon. A USGS study of 534 Chester County wells, sampled 1986–1997, found a median of 1,400 pCi/L of radon in water. In that study, 89% of wells were above 300 pCi/L and 11% were above 5,000. Levels were highest in schist, quartzite, and gneiss. Radon in water isn’t in the standard packages and needs its own bottle. Ask the lab, or see DEP’s Radon Division (800-237-2366).
Arsenic, uranium, and acidic water. The USGS Chester County Ground-Water Atlas (2004) found arsenic mostly in the county’s Triassic sedimentary rocks. There, 9% of samples exceeded the federal limit. Uranium was elevated mainly in Triassic sedimentary and carbonate rocks, and radium in quartzite and schist. 64% of samples were acidic (pH below 6.5), which can pull lead and copper out of plumbing. Manganese was over the secondary standard in 19% of samples and iron in 11%.
Nitrate. About 11% of nitrate samples in the atlas were over the 10 mg/L limit. USGS’s 1980–2008 county monitoring report, run with the county, tied high nitrate to farmland and septic areas. It also found elevated chloride near salt storage and highways.
TCE, other VOCs, and PFAS. In the atlas, 2% of samples were over the limit for TCE, and none exceeded the MTBE advisory. Higher VOC readings sat near known sources. The best-known source is the Bishop Tube site in East Whiteland Township (Malin Rd., south of Route 30). DEP is cleaning up TCE and PFAS there, and its 2022 remedy includes a residential drinking water supply. The DEP project officer is Dustin Armstrong (484-250-5723). CCHD also has a TCE in drinking water page and a list of Superfund sites in the county. PFAS isn’t in any standard package. It’s a separate test, and our PFAS page covers which method to ask for.
These numbers describe the county, not your lot. Results change from one well to the next and from one rock type to the next, so only your own test tells you.
New wells and home sales
New wells. Under CCHD’s Chapter 500, §501 rules (effective November 12, 2014), every new well needs a county permit and a written Approval to Use within 90 days of drilling. A home on a new well can’t be occupied until the well is approved. A CCHD-licensed driller, a licensed pump installer, or a trained employee of a DEP-certified lab must collect the sample. A DEP-certified lab must test it. The panel covers total coliform, nitrate, pH, arsenic (0.010 mg/L), iron, manganese, chloride, TDS, turbidity, and a list of VOCs including TCE and PCE. Treatment is required if bacteria, turbidity, nitrate, arsenic, or VOCs are over the limits, or if pH is outside 5.5–8.5. On the county’s fee schedule, a new well permit is $300 and each additional well is $175. An older well being reused for new construction needs a driller’s letter and a water test. See CCHD’s conditions for well approval.
Home sales. We found no point-of-sale well test in Chapter 500, and Pennsylvania has no statewide one. Testing at sale comes from the lender and the purchase agreement. Ask the underwriter which lab and tests they accept before anyone collects a sample. Our home purchase / lender page covers chain of custody.
Mail-in kits that email a PDF
If you can’t reach a lab during business hours, or you want a wide panel in one box, independent mail-in labs ship to Chester County. Listed prices checked October 22, 2026:
- Tap Score / SimpleLab Essential Well: $209.
- National Testing Laboratories WaterCheck Basic: $220. Next-day return shipping isn’t included, so budget for it on the bacteria bottle.
These cost more than Penn State’s $70 package. They make sense when you want metals, minerals, and VOCs at once with a readable report. Radon in water and PFAS are separate kits. Ask a lender before using one for a sale.
Side by side for a Chester County well
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| Penn State AASL | Local lab (BSC, H.O. Thompson) | DEP Southeast kit | Mail-in (Tap Score / NTL) | |
|---|---|---|---|---|
| Yearly bacteria + nitrate | $70 | Call (H.O. Thompson: bacteria only) | Bacteria only. Call | $209–$220 (broad panel) |
| Arsenic | $30 add-on, or in the $220 Extensive | Ask | No | Included |
| Chain of custody for a sale | No | Ask. Both work with real estate | Ask | Ask the lender first |
| Sales visit? | No | No | No | No |
Remind me to test my well every year
CDC and EPA say to test a private well at least once a year. We’ll send one email a year, about when your test is due, with your state’s lab options.
Thanks, you’re on the list. We’ll email you once a year when it’s time to test your well. Nothing else.
What to do in Chester County
- Each spring, test bacteria plus nitrate. Penn State’s WD04 is $70. To drop off locally, call BSC Labs (610-444-9850) or H.O. Thompson (610-593-5030) for a quote.
- Test arsenic, uranium, and radon in water once if you never have, especially in Triassic sedimentary or schist and quartzite areas.
- Check pH and add lead/copper if your water is acidic or your plumbing is older.
- Near Bishop Tube or another solvent site? Call DEP’s project officer, then test VOCs and PFAS at an accredited lab.
- Want a PDF without driving? Use Tap Score / SimpleLab or National Testing Laboratories. If anything is over a limit, call CCHD (610-344-6225), not a softener salesman.
Not this if…
- You’re on public water. Your water system tests it and publishes a yearly report.
- You’re drilling a new well. CCHD’s Approval to Use sampling has to be collected by a licensed driller, pump installer, or trained lab employee. Don’t collect it yourself.
- A lender named a lab and a chain-of-custody form. Use that lab.
- Someone offered a free in-home “test” that ends in a softener pitch. See the Home Depot free kit comparison.
Related: Pennsylvania well testing · Oakland County, MI · How to read a well water report · PFAS 533 / 537.1 · Home purchase / lender · back to the directory.