Is Cincinnati, OH tap water safe?
Supplied by Cincinnati Public Water System · serves 800,000 people (244,716 connections) · Surface water · EPA ID OH3102612
Data: U.S. EPA · How we read the data · How we check it
Summary
PFAS above the 2024 federal limits. Systems have until 2029 to meet the PFAS limits.
Is it an emergency? No: PFAS limits are about years of exposure, not a glass of water, 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 5.15 ppt vs a limit of 4 ppt, where ppt = parts per trillion).
- Lead
- Below action level2.05 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 ending Jun 2026. 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.
- 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 Cincinnati Public Water System's water quality report (Consumer Confidence Report, from the utility). It lists every regulated contaminant tested, including ones not on this page. Questions: (513) 591-7968.
PFAS (“forever chemicals”)
EPA UCMR 5: 2 entry points tested May 2023 to Feb 2024. "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 | 5.15 ppt 1.29× the limit |
| PFHxS Not detected Limit 10 ppt | – |
| 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 | 0.0019 |
| PFBS Detected, below limit Guideline 2,000 ppt | 3.9 ppt |
| PFBA Detected, below limit Guideline 6,000 ppt | 5.15 ppt |
| PFHxA Not detected Guideline 3,000 ppt | – |
What the utility says it is doing: The utility says PFOA and PFOS at its Bolton plant are slightly above the regulatory limits, while the Miller plant is below them. It has increased monitoring, received a grant to study Bolton treatment options, and says additional treatment may be installed.
Source: PFAS - Greater Cincinnati Water Works. 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 95% of the Ohio systems EPA tested.
29 PFAS tested, 3 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 6 samples (reporting limit 9 ppb). About lithium.
Lead and copper
Latest 90th percentile: 2.05 ppb lead (Jan 2026 – Jun 2026). Below action level
3 reported results in EPA's records are far above anything physically plausible (likely a unit or data-entry error) and are not used in the summary.
Highest since 2016: 12.2 ppb (Dec 2019).
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2026 – Jun 2026 | 2.05 ppb |
| Jul 2025 – Dec 2025 | 1.9 ppb |
| Jan 2025 – Jun 2025 | 1.4 ppb |
Earlier results (9)
| Jul 2024 – Dec 2024 | 2.32 ppb |
| Jan 2024 – Jun 2024 | 1.05 ppb |
| Jul 2023 – Dec 2023 | 2.84 ppb |
| Jan 2023 – Jun 2023 | 3.39 ppb |
| Jul 2022 – Dec 2022 | 3.4 ppb |
| Jan 2022 – Jun 2022 | 3.96 ppb |
| Jul 2021 – Dec 2021 | 7.7 ppb |
| Jan 2021 – Jun 2021 | 3.33 ppb |
| Jul 2020 – Dec 2020 | 6 ppb |
Copper 90th percentile: 37.6 ppm (Dec 2005), action level 1,300 ppb.
Lead service lines: Cincinnati Public Water System's inventory lists 30,000 lead (as of 2026-08-26). It reports 10,000 lead lines replaced since 2018-02. Figures are approximate, as the utility published them.
Look up your address · Source (the utility, collected by us on Nov 14, 2026, not EPA data) · Checking your own line
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
No violations on record in EPA's Safe Drinking Water Information System.
Earlier EPA testing (2013–2020)
| Contaminant | Highest | Guideline |
|---|---|---|
| 1,4-Dioxane | 0.81 ppb | 0.35 ppb |
| Vanadium | 0.72 ppb | 21 ppb |
| Strontium | 0.24 ppm | 1.5 ppm |
| Chlorate | 41 ppb | 210 ppb |
| Chromium-6 | 0.22 ppb | – |
| Molybdenum | 4.9 ppb | 40 ppb |
Where it serves
Cincinnati
58 ZIP codes the system reported serving
45001, 45002, 45013, 45014, 45030, 45040, 45041, 45052, 45069, 45140, 45174, 45202, 45203, 45204, 45205, 45206, 45207, 45208, 45209, 45211, 45212, 45213, 45214, 45215, 45216, 45217, 45218, 45219, 45220, 45221, 45223, 45224, 45225, 45226, 45227, 45228, 45229, 45230, 45231, 45232, 45233, 45236, 45237, 45238, 45239, 45240, 45241, 45242, 45243, 45244, 45245, 45246, 45247, 45248, 45249, 45251, 45252, 45255
Nearby utilities
- Indian Hill City Public Water System The Village of Indian Hill · 10 mi · PFAS above limit
- Milford City Public Water System Milford · 12 mi · PFAS above limit
- Loveland City Public Water System Loveland · 15 mi · PFAS above limit
- Clermont Public Water System Amelia · 17 mi · PFAS above limit
- Butler County Water District 2 Public Water System Hamilton · 18 mi
- Hamilton Public Water System Hamilton · 18 mi
Questions
Is Cincinnati tap water safe to drink?
Most of Cincinnati gets its water from Cincinnati Public Water System. Cincinnati 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 Cincinnati water have PFAS?
Yes. EPA's 2023–2025 testing of Cincinnati Public Water System found 3 PFAS at least once. The highest entry-point averages were above the federal limit for PFOS: PFOS 5.15 ppt (limit 4 ppt for PFOA and PFOS, 10 ppt for the others).
What is the lead level in Cincinnati water?
The most recent 90th-percentile lead result for Cincinnati Public Water System is 2.05 ppb, for the period ending Jun 2026. 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 OH3102612: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID OH3102612).
- EPA SDWIS download: the lead results, population and violation records we use.
- Cincinnati Public Water System's water quality report: the utility's own annual report, including contaminants EPA's national database doesn't carry (link checked Nov 14, 2026). Phone: (513) 591-7968.
- Cincinnati Public Water System website
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.