Is Dayton, OH tap water safe?
Supplied by Dayton Public Water System · serves 141,407 people (50,351 connections) · Surface water · EPA ID OH5703512
Data: U.S. EPA · How we read the data · How we check it
Most of Dayton gets its water from Dayton Public Water System. Parts of the city are served by a smaller system: Dayton VA Bldg 410 Water System (125 people). Your water bill names your system.
Summary
PFAS above the 2024 federal limits, plus lead above the action level. Systems have until 2029 to meet the PFAS limits.
Is it an emergency? No: these findings are about longer-term exposure, and nothing in EPA's data calls for you to stop drinking the water today. If your utility ever issues a boil-water or do-not-drink notice, follow it.
- PFAS
- Above limitPFOS above the federal limit in EPA's 2023–2025 testing (PFOS 7.5 ppt vs a limit of 4 ppt, where ppt = parts per trillion).
- Lead
- Above action level470 ppb (parts per billion) at the 90th percentile: 9 in 10 homes sampled were at or below it. Action level 15 ppb, falling to 10 ppb in Nov 2027. Monitoring period Jan 2024 – now, still in progress (results reported so far). Your home's pipes can make yours higher.
- Violations
- None health-basedNo health-based violations since 2016.
- Pregnant, or mixing baby formula with tap water? Babies drink more water for their size, so PFAS exposure matters more for them. Consider bottled water or a filter certified for PFAS for formula, and ask your doctor. Health effects.
- To lower your PFAS exposure now, a home filter certified for PFAS reduction works (reverse osmosis, or activated carbon certified to NSF/ANSI 53 or 58). Filters for these results.
- Lead was above the action level in some homes sampled. Built before 1986, or not sure what your service line is made of? Check your service line and test your tap. Utility data can't show your pipes.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read Dayton Public Water System's annual water quality report (Consumer Confidence Report). It lists every regulated contaminant tested and is usually on the utility's website or mailed with your bill, and you can also request it at (937) 333-6099. EPA: how to find it.
PFAS (“forever chemicals”)
EPA UCMR 5: 2 entry points tested Mar 2023 to Dec 2023. "Average" is the highest entry-point average (non-detects counted as zero), the way EPA compares UCMR 5 results to the limits. ppt = parts per trillion. These results do not determine compliance.
| Contaminant | Highest average |
|---|---|
| PFOA Not detected Limit 4 ppt | – |
| PFOS Above limit Limit 4 ppt | 7.5 ppt 1.88× the limit |
| PFHxS Detected, below limit Limit 10 ppt | 8.45 ppt 84% of the limit |
| PFNA Not detected Limit 10 ppt | – |
| HFPO-DA (GenX) Not detected Limit 10 ppt | – |
| Hazard Index (a combined score for PFHxS, PFNA, GenX and PFBS, where above 1 is over the limit) Detected, below limit Limit 1 | 0.84 |
| PFBS Detected, below limit Guideline 2,000 ppt | 0.75 ppt |
| PFBA Not detected Guideline 6,000 ppt | – |
| PFHxA Detected, below limit Guideline 3,000 ppt | 3.58 ppt |
| PFPeA Detected, no limit | 3.45 ppt |
What the utility says it is doing: The city says it has removed contaminated wells, expanded its monitoring well network, is developing a PFAS treatment pilot with the U.S. EPA Office of Research and Development, and has received Ohio EPA principal-forgiveness loans for PFAS projects.
Source: PFAS - City of Dayton. Collected by us on Nov 14, 2026, not from EPA's data. Ask the utility for the latest.
For context: the PFOS average is higher than at 96% of the Ohio systems EPA tested.
29 PFAS tested, 5 detected at least once. "Not detected" means below EPA's reporting limit (about 2 to 20 ppt depending on the chemical), not proven zero. PFAS not listed were not detected. The limits for PFHxS, PFNA, GenX and the Hazard Index were proposed for rescission in May 2026. That proposal is not final. Systems have until 2029 to meet the limits.
Lithium
Not detected in 8 samples (reporting limit 9 ppb). About lithium.
Lead and copper
Latest 90th percentile: 470 ppb lead (Jan 2024 – now (in progress)). Above action level
1 reported result in EPA's records is far above anything physically plausible (likely a unit or data-entry error) and is not used in the summary.
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2024 – now (in progress) | 470 ppb |
| Jan 2021 – Dec 2023 | 0 ppb |
| Jan 2018 – Dec 2020 | 4 ppb |
Earlier results (9)
| Jan 2015 – Dec 2017 | 3.8 ppb |
| Jan 2012 – Dec 2014 | 3 ppb |
| Jan 2009 – Dec 2011 | 0 ppb |
| Jan 2008 – Dec 2010 | 0 ppb |
| Jan 2005 – Dec 2007 | 5.8 ppb |
| Jan 2003 – Dec 2005 | 5.8 ppb |
| Jun 2005 – Sep 2005 | Reported value looks erroneous |
| Jan 2003 – Dec 2003 | 5.8 ppb |
| Jan 2002 – Dec 2002 | 4.1 ppb |
Lead comes from pipes and fixtures, not the source water, so it varies home to home. The 90th percentile means 9 in 10 sampled homes were at or below it. More on lead.
Violations
Health-based violations mean a contaminant exceeded a limit or a required treatment step was missed. Monitoring and reporting violations mean required tests or reports were late or missing, so the water's quality during that time is unknown. The total includes every violation in EPA's records, most of them paperwork.
Earlier EPA testing (2013–2020)
| Contaminant | Highest | Guideline |
|---|---|---|
| Strontium | 0.88 ppm | 1.5 ppm |
| 1,4-Dioxane | 0.94 ppb | 0.35 ppb |
| Chromium-6 | 0.24 ppb | – |
| Molybdenum | 5.59 ppb | 40 ppb |
Where it serves
Dayton
25 ZIP codes the system reported serving
45315, 45322, 45377, 45402, 45403, 45404, 45405, 45406, 45408, 45409, 45410, 45414, 45415, 45416, 45417, 45418, 45419, 45420, 45424, 45426, 45427, 45428, 45431, 45432, 45439
Nearby utilities
- Dayton VA Bldg 410 Water System Dayton · same area · PFAS above limit
- Montgomery County Water Services 2 Public Water System Trotwood · 6 mi
- Montgomery County Water Services 1 Public Water System Kettering · 7 mi · PFAS above limit
- Wright-Patterson AFB Area A Public Water System Wright-Patterson AFB · 8 mi · PFAS above limit
- Wright-Patterson AFB Area B Public Water System Wright-Patterson AFB · 8 mi · PFAS above limit
- Bellbrook Water Works Bellbrook · 12 mi · PFAS above limit
Questions
Is Dayton tap water safe to drink?
Most of Dayton gets its water from Dayton Public Water System. Dayton Public Water System has no health-based violations since 2016. EPA testing found PFAS above the 2024 federal limits, which systems must meet by 2029. Federal data can't tell you about your own pipes: lead comes from service lines and plumbing, so test your tap if your home was built before 1986. For the official word, read the utility's annual Consumer Confidence Report.
Does Dayton water have PFAS?
Yes. EPA's 2023–2025 testing of Dayton Public Water System found 5 PFAS at least once. The highest entry-point averages were above the federal limit for PFOS: PFOS 7.5 ppt (limit 4 ppt for PFOA and PFOS, 10 ppt for the others).
What is the lead level in Dayton water?
The most recent 90th-percentile lead result for Dayton Public Water System is 470 ppb, for the monitoring period that began Jan 2024 (still in progress). The federal action level is 15 ppb, falling to 10 ppb in November 2027. The 90th percentile means 9 in 10 homes sampled were at or below this number. Individual homes can be higher.
Check these numbers yourself
Every figure on this page comes from public EPA records. You don't have to take our word for it:
- EPA's own report for OH5703512: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID OH5703512).
- EPA SDWIS download: the lead results, population and violation records we use.
- The utility's annual water quality report (Consumer Confidence Report): ask Dayton Public Water System at (937) 333-6099, or see EPA's guide to finding it.
Found something that doesn't match? Tell us and we'll check it against EPA's records. How we check our data.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.