York County Water Quality: 4 Cities Ranked by the Records

Name: York County Water Quality Data (2026)
Creator: PurityMap
License: https://creativecommons.org/licenses/by/4.0/

York County, South Carolina: 4 city reports built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.

Find my system Open on the map Private wells in York 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.

Lead (90th percentile)Detected in 1 system of 4 tested15 µg/L federal action level · US EPAHighest2 µg/L

ROCK HILL CITY OF (SC4610002)2 µg/LMonitoring period: 2021–2023
FORT MILL TOWN OF (SC4610003)Not detectedMonitoring period: 2022–2024
YORK CITY OF (SC4610001)Not detectedMonitoring period: 2021–2023
YORK COUNTY WEST WD (SC4620003)Not detectedMonitoring period: 2018–2020

Perfluorohexanoic acid (PFHxA)Detected in 4 systems400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLEHighest4.4 ng/L

FORT MILL TOWN OF (SC4610003)4.4 ng/LSample date: 2024-04-30 to 2024-12-26
ROCK HILL CITY OF (SC4610002)4.4 ng/LSample date: 2023-10-10 to 2024-07-09
YORK COUNTY WEST WD (SC4620003)4.2 ng/LSample date: 2023-01-23 to 2023-10-11
YORK CITY OF (SC4610001)3.4 ng/LSample date: 2024-04-10 to 2024-11-20

Perfluoropentanoic acid (PFPeA)Detected in 4 systemsNo federal or state limit; shown for transparencyHighest5.9 ng/L

ROCK HILL CITY OF (SC4610002)5.9 ng/LSample date: 2023-10-10 to 2024-07-09
YORK COUNTY WEST WD (SC4620003)4.9 ng/LSample date: 2023-01-23 to 2023-10-11
FORT MILL TOWN OF (SC4610003)4.6 ng/LSample date: 2024-04-30 to 2024-12-26
YORK CITY OF (SC4610001)3.9 ng/LSample date: 2024-04-10 to 2024-11-20

28 substances tested, none detected in any systemShow

Tested in these 4 systems: FORT MILL TOWN OF (SC4610003), ROCK HILL CITY OF (SC4610002), YORK CITY OF (SC4610001), YORK COUNTY WEST WD (SC4620003)

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)
Perfluorobutanesulfonic acid (PFBS)
Perfluorobutanoic acid (PFBA)
Perfluorodecanoic acid (PFDA)
Perfluorododecanoic acid (PFDoA)
Perfluoroheptanesulfonic acid (PFHpS)
Perfluoroheptanoic acid (PFHpA)
Perfluorohexanesulfonic acid (PFHxS)
Perfluorononanoic acid (PFNA)
Perfluorooctanesulfonic acid (PFOS)
Perfluorooctanoic acid (PFOA)
Perfluoropentanesulfonic acid (PFPeS)
Perfluorotetradecanoic acid (PFTA)
Perfluorotridecanoic acid (PFTrDA)
Perfluoroundecanoic acid (PFUnA)

4 cities

Cities ranked by the records

1
Fort MillFORT MILL TOWN OF (SC4610003)
PFAS detected, within limit
Open city report →
2
YorkYORK CITY OF (SC4610001)
PFAS detected, within limit
Open city report →
3
Rock HillROCK HILL CITY OF (SC4610002)
PFAS detected, within limitLead below action level
Open city report →
4
Lake WylieYORK COUNTY WEST WD (SC4620003)
PFAS detected, within limit
Open city report →

Showing 4 of 4 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 York CountyPFAS detected in 4 of 4 cities; none had a sample above a 2024 EPA limit

4.0 ng/L federal MCL · PFOS, ng/LPFAS in South Carolina

Lead

0of 4 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 South Carolina

Who supplies the county

Largest water systems

Rock HillROCK HILL CITY OF (SC4610002) · SC4610002
89,850 served
Fort MillFORT MILL TOWN OF (SC4610003) · SC4610003
25,000 served
Lake WylieYORK COUNTY WEST WD (SC4620003) · SC4620003
18,273 served
YorkYORK CITY OF (SC4610001) · SC4610001
11,137 served

Questions

Frequently asked

How does York County tap water compare across cities?

PurityMap ranks 4 cities in York 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 Fort Mill's main water system: FORT MILL TOWN OF (SC4610003) · PWSID SC4610003 · Purity Score 100 (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 York County cities had a PFAS sample above a 2024 EPA limit?

None of the 4 York County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing. PFAS were detected below the limit in 4.

Is there lead in York County tap water?

Utilities report lead as a 90th-percentile result from home taps. 1 of 4 York 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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