Warren County Water Quality: 2 Cities Ranked by the Records
Warren County, New Jersey: 2 city reports built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.
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 1 system of 2 tested4.0 ng/L federal MCL (2024) · US EPAHighest9 ng/L
- WASHINGTON TOWNSHIP MUA9 ng/LSample date: 2025-03-12 to 2025-09-17
- HACKETTSTOWN MUANot detected · below 4.0 ng/L lab reporting limitSample date: 2024-06-18 to 2024-12-03
Lead (90th percentile)Detected in 1 system of 2 tested15 µg/L federal action level · US EPAHighest1 µg/L
- HACKETTSTOWN MUA1 µg/LMonitoring period: 2025–2025
- WASHINGTON TOWNSHIP MUANot detectedMonitoring period: 2021–2023
Perfluorobutanesulfonic acid (PFBS)Detected in 1 system of 2 tested2,000 ng/L EPA health advisory (screening, not a legal limit) · US EPAHighest10.9 ng/L
- WASHINGTON TOWNSHIP MUA10.9 ng/LSample date: 2025-03-12 to 2025-09-17
- HACKETTSTOWN MUANot detected · below 3.0 ng/L lab reporting limitSample date: 2024-06-18 to 2024-12-03
Perfluorohexanoic acid (PFHxA)Detected in 1 system of 2 tested400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLEHighest5.6 ng/L
- WASHINGTON TOWNSHIP MUA5.6 ng/LSample date: 2025-03-12 to 2025-09-17
- HACKETTSTOWN MUANot detected · below 3.0 ng/L lab reporting limitSample date: 2024-06-18 to 2024-12-03
Perfluoroheptanoic acid (PFHpA)Detected in 1 system of 2 testedNo federal or state limit; shown for transparencyHighest3.2 ng/L
- WASHINGTON TOWNSHIP MUA3.2 ng/LSample date: 2025-03-12 to 2025-09-17
- HACKETTSTOWN MUANot detected · below 3.0 ng/L lab reporting limitSample date: 2024-06-18 to 2024-12-03
Perfluoropentanoic acid (PFPeA)Detected in 1 system of 2 testedNo federal or state limit; shown for transparencyHighest5.5 ng/L
- WASHINGTON TOWNSHIP MUA5.5 ng/LSample date: 2025-03-12 to 2025-09-17
- HACKETTSTOWN MUANot detected · below 3.0 ng/L lab reporting limitSample date: 2024-06-18 to 2024-12-03
25 substances tested, none detected in any systemShow
Tested in these 2 systems: HACKETTSTOWN MUA, WASHINGTON TOWNSHIP MUA
- 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)
- Perfluorobutanoic acid (PFBA)
- Perfluorodecanoic acid (PFDA)
- Perfluorododecanoic acid (PFDoA)
- Perfluoroheptanesulfonic acid (PFHpS)
- Perfluorohexanesulfonic acid (PFHxS)
- Perfluorononanoic acid (PFNA)
- Perfluorooctanesulfonic acid (PFOS)
- Perfluoropentanesulfonic acid (PFPeS)
- Perfluorotetradecanoic acid (PFTA)
- Perfluorotridecanoic acid (PFTrDA)
- Perfluoroundecanoic acid (PFUnA)
Cities ranked by the records
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.
0of 2 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 New JerseyLargest water systems
- WashingtonWASHINGTON TOWNSHIP MUA · NJ081800448,000 served
- HackettstownHACKETTSTOWN MUA · NJ210800122,000 served
Frequently asked
How does Warren County tap water compare across cities?
PurityMap ranks 2 cities in Warren 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 Hackettstown's main water system: HACKETTSTOWN MUA · PWSID NJ2108001 · Purity Score 99 (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 Warren County cities have PFAS above the federal limit?
1 city of 2 had at least one regulated PFAS (PFOA, PFOS or PFHxS) measured above the 2024 federal limit in EPA's UCMR 5 testing, including Washington (PFOA 9 ng/L). PFAS were detected at any level in 1.
Is there lead in Warren County tap water?
Utilities report lead as a 90th-percentile result from home taps. 1 of 2 Warren 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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