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Cincinnati, OH · 775,655 people served · EPA data 2021–2026

Tap water quality in Cincinnati, Ohio

Cincinnati's water systems logged 3 health-based EPA violations in 2021–2026, most recently in 2025 — a modest record, with stage 1 disinfectants and disinfection byproducts rule the issue found. For context, Ohio's systems average 1.3 health-based violations each.

CFair
Cincinnati water grade: C
Fair — our A–F grade from this city's EPA compliance record, relative to Ohio and the nation. How we grade →
Health-based violations, 2021–20263
Stage 1 Disinfectants And Disinfection Byproducts Rule2
Lead And Copper Rule Revisions1
Cincinnati Public Water System750,200 served
Indian Hill City Pws15,000 served
Wyoming City Pws9,700 served
Chateau Estates Mhp Pws430 served
Ohio quality rank#36 / 51 (81.0/100)
Ohio avg hardness130 PPM (hard)
Want to know what's actually in your Cincinnati water?

Averages describe states, not your faucet. A certified home water test screens for lead, nitrates, bacteria and dozens of other contaminants — the same categories EPA regulates.

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Cincinnati tap water FAQ

Is tap water safe to drink in Cincinnati?

Cincinnati's systems logged 3 health-based violations in 2021–2026, most commonly stage 1 disinfectants and disinfection byproducts rule. A violation is a red flag for a period of time, not a permanent condition — your utility's current Consumer Confidence Report shows today's status, and a certified home test shows what's at your tap.

Who supplies Cincinnati's water?

Cincinnati Public Water System (serving about 750,200 people); Indian Hill City Pws (serving about 15,000 people); Wyoming City Pws (serving about 9,700 people); Chateau Estates Mhp Pws (serving about 430 people). Data: EPA Safe Drinking Water Information System, July 2026.

How hard is the water in Cincinnati?

City-level hardness isn't published in a single federal dataset, but Ohio averages 130 PPM — "hard" on the USGS scale. Your utility's water quality report lists Cincinnati's exact hardness, or a $10 test strip tells you in a minute. If it comes back over 120 PPM, see our water softener guidance in the purification calculator.

Do I need a water filter in Cincinnati?

With 3 health-based violations on record in 2021–2026, a certified filter is reasonable insurance here: reverse osmosis ($150–$1,300 installed, Angi 2026) covers lead, nitrates and PFAS at the tap. Test first ($50–$200) so you buy for what's actually present.

Want to know what's actually in your Cincinnati water?

Averages describe states, not your faucet. A certified home water test screens for lead, nitrates, bacteria and dozens of other contaminants — the same categories EPA regulates.

Test your water at home

We may earn a commission if you request quotes through this link. It costs you nothing and never affects the data we publish.