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Janesville, WI · 65,913 people served · EPA data 2021–2026

Tap water quality in Janesville, Wisconsin

Janesville's water systems logged 1 health-based EPA violation in 2021–2026, most recently in 2024 — a modest record, with lead and copper rule revisions the issue found. For context, Wisconsin's systems average 1.4 health-based violations each.

CFair
Janesville water grade: C
Fair — our A–F grade from this city's EPA compliance record, relative to Wisconsin and the nation. How we grade →
Health-based violations, 2021–20261
Lead And Copper Rule Revisions1
Janesville Water Utility64,415 served
Rockvale Mhp1,200 served
Caravilla Education And Rehab Center298 served
Wisconsin quality rank#43 / 51 (77.7/100)
Wisconsin avg hardness140 PPM (hard)
Want to know what's actually in your Janesville 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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Janesville tap water FAQ

Is tap water safe to drink in Janesville?

Janesville's systems logged 1 health-based violation in 2021–2026, most commonly lead and copper rule revisions. 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 Janesville's water?

Janesville Water Utility (serving about 64,415 people); Rockvale Mhp (serving about 1,200 people); Caravilla Education And Rehab Center (serving about 298 people). Data: EPA Safe Drinking Water Information System, July 2026.

How hard is the water in Janesville?

City-level hardness isn't published in a single federal dataset, but Wisconsin averages 140 PPM — "hard" on the USGS scale. Your utility's water quality report lists Janesville'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 Janesville?

With 1 health-based violation 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 Janesville 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.