Delaware County Water Quality: 2 Cities Ranked by the Records
Delaware County, Ohio: 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.
LithiumDetected in 2 systems10 µg/L EPA health reference level (screening, not a legal limit) · US EPAHighest15.4 µg/L
- DELAWARE CITY PWS15.4 µg/LSample date: 2023-05-16 to 2024-02-05
- DEL-CO WATER COMPANY, INC.12.9 µg/LSample date: 2023-07-11 to 2024-04-08
Perfluorooctanoic acid (PFOA)Detected in 1 system of 2 tested4.0 ng/L federal MCL (2024) · US EPAHighest4.2 ng/L
- DEL-CO WATER COMPANY, INC.4.2 ng/LSample date: 2023-07-11 to 2024-04-08
- DELAWARE CITY PWSNot detected · below 4.0 ng/L lab reporting limitSample date: 2023-05-16 to 2024-02-05
Lead (90th percentile)Detected in 1 system of 2 tested15 µg/L federal action level · US EPAHighest0.825 µg/L
- DEL-CO WATER COMPANY, INC.0.825 µg/LMonitoring period: 2022–2024
- DELAWARE CITY PWSNot detectedMonitoring period: 2022–2024
Perfluorobutanesulfonic acid (PFBS)Detected in 1 system of 2 tested2,000 ng/L EPA health advisory (screening, not a legal limit) · US EPAHighest4.3 ng/L
- DEL-CO WATER COMPANY, INC.4.3 ng/LSample date: 2023-07-11 to 2024-04-08
- DELAWARE CITY PWSNot detected · below 3.0 ng/L lab reporting limitSample date: 2023-05-16 to 2024-02-05
Perfluorohexanoic acid (PFHxA)Detected in 1 system of 2 tested400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLEHighest8.7 ng/L
- DEL-CO WATER COMPANY, INC.8.7 ng/LSample date: 2023-07-11 to 2024-04-08
- DELAWARE CITY PWSNot detected · below 3.0 ng/L lab reporting limitSample date: 2023-05-16 to 2024-02-05
Perfluorobutanoic acid (PFBA)Detected in 1 system of 2 testedNo federal or state limit; shown for transparencyHighest10.7 ng/L
- DEL-CO WATER COMPANY, INC.10.7 ng/LSample date: 2023-07-11 to 2024-04-08
- DELAWARE CITY PWSNot detected · below 5.0 ng/L lab reporting limitSample date: 2023-05-16 to 2024-02-05
Perfluoropentanoic acid (PFPeA)Detected in 1 system of 2 testedNo federal or state limit; shown for transparencyHighest6.3 ng/L
- DEL-CO WATER COMPANY, INC.6.3 ng/LSample date: 2023-07-11 to 2024-04-08
- DELAWARE CITY PWSNot detected · below 3.0 ng/L lab reporting limitSample date: 2023-05-16 to 2024-02-05
24 PFAS tested, none detected in any systemShow
Tested in these 2 systems: DEL-CO WATER COMPANY, INC., DELAWARE CITY PWS
- 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)
- 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)
- 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 OhioLargest water systems
Frequently asked
How does Delaware County tap water compare across cities?
PurityMap ranks 2 cities in Delaware 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 Delaware's main water system: DELAWARE CITY PWS · PWSID OH2100311 · 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 Delaware County cities had a PFAS sample above a 2024 EPA limit?
1 of 2 Delaware County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including Powell (PFOA 4.2 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 1.
Is there lead in Delaware County tap water?
Utilities report lead as a 90th-percentile result from home taps. 1 of 2 Delaware 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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