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Wetherill Estates

What EPA’s and Pennsylvania’s records show in this utility’s water: PFAS; nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.

Serves
250 people
Connections
75
Water source
Groundwater
Based in
Exton, PA
County
Chester
Owner
Private
Hardness
Moderately hard
The ZIP code it serves

19425

The short answer

1 result is above EPA’s new limit, which takes effect in 2029, and 1 more is above the health goal. The worst: PFOA, above EPA’s new limit (2029). 2 health-based violations since 2016.

What handles it

What was found

PFAS: Pennsylvania’s own results under its PFAS rule, entry point samples taken from March 13, 2025 to July 7, 2026.

Copper: EPA’s file records a utility’s copper only when it exceeds the action level. The last here was 2.1 ppm, for the period ending Dec. 31, 1999. None since is on file, so it is not counted as a current finding.

Nitrate, total trihalomethanes (TTHM), haloacetic acids (HAA5), arsenic, chromium (total), fluoride and uranium: Pennsylvania’s own results, samples taken from Jan. 9, 2020 to Aug. 10, 2026, with EPA’s 2012 to 2019 file for earlier years.

PFAS: PFOA, PFOS and PFBS were found, of the six PFAS in EPA’s 2024 drinking water rule; their results are below.

EPA’s 2024 PFAS rule, compound by compound

PFASEPA’s limitResult
PFOA4.0 pptAbove EPA’s new limit (2029)5.2 ppt highest, found in 7 of 7 samples. Details
PFOS4.0 pptAbove the health goal4.0 ppt highest, found in 7 of 7 samples. Details
PFHxS10 pptNot foundNot found in any of 7 samples
PFNA10 pptNot foundNot found in any of 7 samples
HFPO-DA (GenX)10 pptNot foundNot found in any of 7 samples
PFBSIndex onlyBelow EPA’s limits5.7 ppt highest, found in 7 of 7 samples. Details
Results from Pennsylvania’s own PFAS monitoring, samples where water enters the pipes; each compound’s card has its four-quarter averages, the way limits are judged. The limits are EPA’s 2024 rule, with compliance due from 2029; EPA has since proposed changes to some of them, explained on each compound’s page. Pennsylvania’s own limits for PFOA and PFOS are in force now. PFBS has no limit of its own and counts only toward EPA’s Hazard Index, which TapBuff works out only from UCMR 5’s averages, so it isn’t given here.

About PFAS certifications

NSF’s PFAS claims are tested to below 20 ppt. EPA’s limit is 4.0 ppt, and EPA says no certification yet shows a filter reaching its levels.

Above EPA’s new limit, which takes effect in 20291

PFOA

Comes from the source

Above EPA’s new limit (2029)

5.2ppt

Highest sample, March 17, 2026; found in 7 of 7

2026 average: 4.2 ppt

The highest sample was 5.2 ppt, above EPA’s new limit of 4.0 ppt, which takes effect in 2029. EPA’s health goal is zero. Compliance will be judged on a running annual average, not one sample. Averaged over four quarters at one entry point, the way both Pennsylvania’s limit and EPA’s are judged, the highest was 4.7 ppt, for the year to Dec. 31, 2025: below Pennsylvania’s limit of 14 ppt and above EPA’s new limit of 4.0 ppt. In 2026, the latest year on file, its three samples averaged 4.2 ppt.

What handles it

Above the health goal1

PFOS

Comes from the source

Above the health goal

4.0ppt

Highest sample, Sept. 24, 2025; found in 7 of 7

2026 average: 3.5 ppt

The highest sample was 4.0 ppt: below EPA’s new limit of 4.0 ppt, which takes effect in 2029, but above its health goal of zero. Averaged over four quarters at one entry point, the way both Pennsylvania’s limit and EPA’s are judged, the highest was 3.7 ppt, for the year to March 31, 2026: below Pennsylvania’s limit of 18 ppt and below EPA’s new limit of 4.0 ppt. In 2026, the latest year on file, its three samples averaged 3.5 ppt.

What handles it

Below EPA’s limits4

Nitrate

Comes from the source

Below EPA’s limits

8.7ppm

Highest sample; found in 27 of 27

2026 average: 6.6 ppm

The highest sample, in 2020, was 8.7 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its three samples averaged 6.6 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 9.0 ppm, in 2018.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

62.1ppb

Highest yearly average, 2021 to 2026

2026, one sample: 46.4 ppb

Averaged by year, the highest was 62.1 ppb, in 2024, below EPA’s legal limit of 80 ppb. In 2026, the latest year on file, its one sample was 46.4 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 25.9 ppb, in 2018.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

16.2ppb

Highest yearly average, 2021 to 2026

2026, one sample: 14.3 ppb

Averaged by year, the highest was 16.2 ppb, in 2024, below EPA’s legal limit of 60 ppb. In 2026, the latest year on file, its one sample was 14.3 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 12.7 ppb, in 2018.

What handles it

No certification claim covers this compound yet.

PFBS

Comes from the source

Below EPA’s limits

5.7ppt

Highest sample, Sept. 24, 2025; found in 7 of 7

2026 average: 5.2 ppt

The highest sample was 5.7 ppt, below EPA’s hazard index benchmark of 2,000 ppt. PFBS has no legal limit or health goal of its own. In 2026, the latest year on file, its three samples averaged 5.2 ppt.

What handles it

7 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.

From routine monitoring

  • Arsenic
  • Chromium (total)
  • Fluoride
  • Uranium

PFAS, from Pennsylvania’s own monitoring

  • HFPO-DA (GenX)
  • PFHxS
  • PFNA

What handles it

A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”

  • NSF/ANSI 53

    Claims: PFOA Reduction, PFOS Reduction

    For: PFOA, PFOS

    Other certifiers’ wording: Total PFAS Reduction; Perfluorooctanoic Acid (PFOA); Perfluorooctane Sulfonate (PFOS)

  • NSF/ANSI 58

    Claims: Perfluorooctanoic Acid (PFOA), Perfluorooctane Sulfonate (PFOS)

    For: PFOA, PFOS

At the tap, or for the whole house?

These come with the water itself, so a whole-house system certified for the same claims treats every tap and shower. A filter at the tap treats drinking water for much less. How whole-house systems compare.

Filters with those claims on a certifier’s listing

Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money

Compare five-year costs

The best water filters for PFAS, ranked

Hardness

Moderately hard, typically 91 mg/L (5.3 grains per gallon), across 2 sampling points, in 2022.

Hardness is calcium and magnesium. EPA sets no limit for it: it shows up as scale on fixtures and in water heaters, and as soap that won’t lather. USGS calls water above 60 mg/L moderately hard, above 120 hard and above 180 very hard.

Softeners compared at 5.3 grains per gallon, salt includedSoftener or salt-free conditioner?Pennsylvania water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Groundwater RuleRequired treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR)May 1, 2021 to May 31, 2021—Resolved
Groundwater RuleRequired treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR)April 1, 2021 to April 30, 2021—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 18 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Nitrate, total trihalomethanes (TTHM), haloacetic acids (HAA5), arsenic, chromium (total), fluoride and uranium results here are Pennsylvania’s own from 2020 on, with EPA’s national file for 2012 to 2019. Wetherill Estates’s own annual report, which it must send you every year, has the contaminants this page does not show.

  • Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.

  • What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.

  • Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; Pennsylvania’s results run from Jan. 9, 2020 to Aug. 10, 2026; Pennsylvania’s PFAS results run from March 13, 2025 to July 7, 2026.

Testing your own tap

Wetherill Estates’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab Pennsylvania certifies.

The 3 labs Pennsylvania certifies closest to the area Wetherill Estates serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Brandywine Science Center

    Kennett Square, PA · about 16 miles

    Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics

    (610) 444-9850

  • H.O. Thompson Testing Lab

    Parkesburg, PA · about 17 miles

    Certified for bacteria

    (610) 593-5030

  • Aqua Pennsylvania, Inc.

    Bryn Mawr, PA · about 18 miles

    Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, PFAS, radioactivity

    (610) 525-1400

Penn State Agricultural Analytical Services Laboratory: Drinking water test kits from many county Extension offices, mailed back to the lab overnight with payment. Packages cover bacteria and basic chemistry, with add-ons for nitrate, metals, lead, and mining or gas drilling concerns. The standard package of bacteria, pH and total dissolved solids is $60, or $70 with nitrate; bacteria alone is $40, nitrate $15 and lead $25. Drinking Water Testing, Penn State Agricultural Analytical Services Lab.

All 108 certified labs for Pennsylvania

Sources

PWSID PA1150209. Rebuilt from EPA data on Oct. 18, 2026.

Also in Chester County

All Pennsylvania utilities

What to do next