Union County Water Quality: 2 Cities Ranked by the Records
Union County, North Carolina: 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.
Perfluorooctanesulfonic acid (PFOS)Detected in 1 system of 2 tested4.0 ng/L federal MCL (2024) · US EPAHighest4.9 ng/L
- UNION COUNTY WATER SYSTEM4.9 ng/LSample date: 2023-01-18 to 2023-10-04
- MONROE, CITY OFNot detected · below 4.0 ng/L lab reporting limitSample date: 2023-07-26 to 2024-03-11
Perfluorooctanoic acid (PFOA)Detected in 1 system of 2 tested4.0 ng/L federal MCL (2024) · US EPAHighest4.2 ng/L
- UNION COUNTY WATER SYSTEM4.2 ng/LSample date: 2023-01-18 to 2023-10-04
- MONROE, CITY OFNot detected · below 4.0 ng/L lab reporting limitSample date: 2023-07-26 to 2024-03-11
Perfluorobutanesulfonic acid (PFBS)Detected in 1 system of 2 tested2,000 ng/L EPA health advisory (screening, not a legal limit) · US EPAHighest5.6 ng/L
- MONROE, CITY OF5.6 ng/LSample date: 2023-07-26 to 2024-03-11
- UNION COUNTY WATER SYSTEMNot detected · below 3.0 ng/L lab reporting limitSample date: 2023-01-18 to 2023-10-04
Perfluorohexanoic acid (PFHxA)Detected in 1 system of 2 tested400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLEHighest7.4 ng/L
- UNION COUNTY WATER SYSTEM7.4 ng/LSample date: 2023-01-18 to 2023-10-04
- MONROE, CITY OFNot detected · below 3.0 ng/L lab reporting limitSample date: 2023-07-26 to 2024-03-11
Perfluorobutanoic acid (PFBA)Detected in 2 systemsNo federal or state limit; shown for transparencyHighest6.9 ng/L
- MONROE, CITY OF6.9 ng/LSample date: 2023-07-26 to 2024-03-11
- UNION COUNTY WATER SYSTEM6.5 ng/LSample date: 2023-01-18 to 2023-10-04
Perfluoropentanoic acid (PFPeA)Detected in 1 system of 2 testedNo federal or state limit; shown for transparencyHighest10 ng/L
- UNION COUNTY WATER SYSTEM10 ng/LSample date: 2023-01-18 to 2023-10-04
- MONROE, CITY OFNot detected · below 3.0 ng/L lab reporting limitSample date: 2023-07-26 to 2024-03-11
25 substances tested, none detected in any systemShow
Tested in these 2 systems: MONROE, CITY OF, UNION COUNTY WATER SYSTEM
- 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)
- Lead (90th percentile)
- 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)
- Perfluoroheptanoic acid (PFHpA)
- Perfluorohexanesulfonic acid (PFHxS)
- Perfluorononanoic acid (PFNA)
- 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 North CarolinaLargest water systems
- Indian TrailUNION COUNTY WATER SYSTEM · NC0190413169,685 served
- MonroeMONROE, CITY OF · NC019001043,081 served
Frequently asked
How does Union County tap water compare across cities?
PurityMap ranks 2 cities in Union 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 Monroe's main water system: MONROE, CITY OF · PWSID NC0190010 · Purity Score 97 (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 Union County cities had a PFAS sample above a 2024 EPA limit?
1 of 2 Union County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including Indian Trail (PFOS 4.9 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 2.
Is there lead in Union County tap water?
Utilities report lead as a 90th-percentile result from home taps. 0 of 2 Union 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.
Have Union County water systems had drinking-water violations?
2 cities in Union County have a health-based violation in the federal SDWIS record within about the last ten years. Each city report lists the contaminant, year and whether it was resolved.
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