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Updated 2026-10-15
County water report

Chester County Water Quality: 3 Cities Ranked by the Records

Chester County, Pennsylvania: 3 city reports built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.

Find my systemOpen on the mapPrivate wells in Chester County
Across the county's systems

Highest result for each contaminant

One row per contaminant: the highest result any system in the county reported, against its limit. Open a row for the systems behind it.

Perfluorooctanoic acid (PFOA)Detected in 2 systems of 3 tested4.0 ng/L federal MCL (2024) · US EPAHighest5.9 ng/L
Perfluorooctanesulfonic acid (PFOS)Detected in 1 system of 3 tested4.0 ng/L federal MCL (2024) · US EPAHighest5.1 ng/L
Lead (90th percentile)Detected in 2 systems of 3 tested15 µg/L federal action level · US EPAHighest2 µg/L
Perfluorobutanesulfonic acid (PFBS)Detected in 2 systems of 3 tested2,000 ng/L EPA health advisory (screening, not a legal limit) · US EPAHighest9.8 ng/L
Perfluorohexanoic acid (PFHxA)Detected in 2 systems of 3 tested400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLEHighest9 ng/L
Perfluorobutanoic acid (PFBA)Detected in 3 systemsNo federal or state limit; shown for transparencyHighest57.3 ng/L
Perfluoroheptanoic acid (PFHpA)Detected in 1 system of 3 testedNo federal or state limit; shown for transparencyHighest3.1 ng/L
Perfluoropentanoic acid (PFPeA)Detected in 3 systemsNo federal or state limit; shown for transparencyHighest10.2 ng/L
23 substances tested, none detected in any systemShow

Tested in these 3 systems: AQUA PA WEST CHESTER, PA AMERICAN COATESVILLE, PHOENIXVILLE WATER DEPT

  • 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
  • 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
  • 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
  • 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)
  • 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
  • 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
  • Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
  • Lithium
  • N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
  • N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
  • Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
  • Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
  • Perfluoro-3-methoxypropanoic acid (PFMPA)
  • Perfluoro-4-methoxybutanoic acid (PFMBA)
  • Perfluorodecanoic acid (PFDA)
  • Perfluorododecanoic acid (PFDoA)
  • Perfluoroheptanesulfonic acid (PFHpS)
  • Perfluorohexanesulfonic acid (PFHxS)
  • Perfluorononanoic acid (PFNA)
  • Perfluoropentanesulfonic acid (PFPeS)
  • Perfluorotetradecanoic acid (PFTA)
  • Perfluorotridecanoic acid (PFTrDA)
  • Perfluoroundecanoic acid (PFUnA)
3 cities

Cities ranked by the records

Showing 3 of 3 cities · scores are system-level, not tap tests

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no county score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works.

PFAS in Chester County2 of 3 city reports had a PFAS sample above a 2024 EPA limit
  1. Phoenixville5.1 ng/L
4.0 ng/L federal MCL · PFOS, ng/LPFAS in Pennsylvania
Lead

0of 3 cities above the 15 µg/L action level

Based on each system's 90th-percentile result. Lead from household plumbing isn't in this record.

Lead in Pennsylvania
Who supplies the county

Largest water systems

  1. West ChesterAQUA PA WEST CHESTER · PA1150098
    48,600 served
  2. CoatesvillePA AMERICAN COATESVILLE · PA1150106
    36,960 served
  3. PhoenixvillePHOENIXVILLE WATER DEPT · PA1150077
    16,599 served
Questions

Frequently asked

How does Chester County tap water compare across cities?

PurityMap ranks 3 cities in Chester County by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Coatesville's main water system: PA AMERICAN COATESVILLE · PWSID PA1150106 · Purity Score 98 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.

How many Chester County cities had a PFAS sample above a 2024 EPA limit?

2 of 3 Chester County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including West Chester (PFOA 5.9 ng/L), Phoenixville (PFOA 5.9 ng/L). That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. PFAS were detected at any level in 3.

Is there lead in Chester County tap water?

Utilities report lead as a 90th-percentile result from home taps. 2 of 3 Chester County cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.

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