Drinking water quality · 2024
What's in Dayton, OH tap water
18 contaminants were measured in the Dayton, OH water system's 2024 annual report. Each is shown below against its federal limit — 2 sit at or above that limit.
- Reporting year
- 2024
- Contaminants measured
- 18
- Over federal limit
- 2
- Approaching the limit
- 1
- Worst contaminant
- PFOS
- Service area
- OH
PFAS — EPA UCMR5 (2023–2025)
1 PFAS compound above EPA limits in Dayton, OH
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFOS (Perfluorooctane sulfonic acid)
● Over EPA limit (2.5×)PFHxS (Perfluorohexane sulfonic acid)
● Approaching limit (98%)PFHxA
● Detected (no federal limit)PFPeA
● Detected (no federal limit)PFBS
● Detected (no federal limit)Where your water comes from · EPA SDWIS
Dayton, OH's drinking water comes from ground water under the influence of surface water, drawn from 108 sources.
Source
- DAYTON, CITY OF-OTTAWA P · 51
- DAYTON, CITY OF-MIAMI PL · 33
- DAYTON, CITY OF- OTTAWA PLANT · 10
- DAYTON, CITY OF- MIAMI PLANT · 3
- + 9 more
Treatment
- DAYTON PWS MIAMI PLANT
- DAYTON PWS OTTAWA PLANT
Distribution
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Maximum contaminant level exceededHealth-based2 violations on record · most recent Sep 1992resolved
- Treatment technique violationHealth-based1 violation on record · most recent May 2009resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PFOAPerfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. | 3.57 ng/LAverageSystem-wide | None set | Approaching the limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 28.3 ug/LHighest single sampleSystem-wide | None set | Within the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 7.1 ug/LHighest single sampleSystem-wide | None set | Within the limit |
| BromoformA trihalomethane disinfection byproduct. | Not detected ug/LAverageSystem-wide | None set | None detected |
| BromodichloromethaneA trihalomethane disinfection byproduct. | 1.23 ug/LAverageSystem-wide | None set | Detected — no federal limit |
| ChloroformA trihalomethane formed when chlorine reacts with organic matter in water. | 0.85 ug/LAverageSystem-wide | None set | Detected — no federal limit |
| DibromochloromethaneA trihalomethane disinfection byproduct. | 1.91 ug/LAverageSystem-wide | None set | Detected — no federal limit |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 1.23–1.32 mg/LRangeSystem-wide | 4 mg/LMCL | Within the limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.82–1.18 mg/LRangeSystem-wide | 4 mg/LMCL | Within the limit |
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 1.51 mg/LReported levelSystem-wide | 10 mg/LMCL | Within the limit |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.088 NTUReported levelSystem-wide | None set | Within the limit |
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 0.62–1 mg/LRangeSystem-wide | None set | Detected — no federal limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| CopperA metal that enters water from corroding household plumbing. | 0.044 mg/LReported levelSystem-wide | 1.3 mg/LAction level | Within the limit |
| BariumA metal from erosion of natural deposits and industrial discharge. | 0.058 mg/LReported levelSystem-wide | 2 mg/LMCL | Within the limit |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | Not detected ug/LReported levelSystem-wide | None set | None detected |
People also ask about Dayton, OH's water
+Is Dayton, OH tap water safe to drink in 2024?
The 2024 Consumer Confidence Report for the Dayton, OH water utility lists 2 contaminants at or above the federal limit: PFOS and Perfluorohexanesulfonic acid. Whether that means the water is "unsafe" depends on which contaminant, how long the exposure, and individual health factors. The table on this page shows the measured value, the federal threshold, and the regulated statistic used for compliance.
+What contaminants are in Dayton, OH tap water?
18 contaminants were measured in Dayton, OH's 2024 Consumer Confidence Report, spanning disinfection byproducts, pfas ("forever chemicals"), and metals. 5 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Which contaminants exceed federal limits in Dayton, OH tap water?
2 contaminants in Dayton, OH's 2024 report sit at or above the federal limit: PFOS (2.4× the limit); Perfluorohexanesulfonic acid (1.3× the limit). The EPA enforces these limits against the regulated reporting statistic — typically a running annual average or 90th percentile — not a one-off sample spike.
+What is the worst contaminant in Dayton, OH tap water?
The contaminant with the highest measured value relative to its federal limit in the 2024 report is PFOS, at 2.4× the federal threshold. It belongs to the pfas ("forever chemicals") family of contaminants.
+Are any contaminants in Dayton, OH tap water approaching the federal limit?
One contaminant is between 80% and 100% of the federal limit in this report: PFOA. Approaching means measured but not in violation — a margin that can close quickly if conditions change.
+Where does the data on this page come from?
Every value is transcribed from Dayton, OH's 2024 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Dayton, OH's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2024 report; a new report will replace it once the utility publishes its next annual update.