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Rib Mountain, WI Tap Water Quality 2026

Water quality report for Rib Mountain, WI — PFAS, lead and copper results, violation history and state inspection findings from EPA SDWIS.

A look at Rib Mountain's drinking water using EPA enforcement records: violations, lead and copper results, PFAS sampling and state inspection findings.

Main Utility: Rib Mountain Water Utility PWSID: WI7370660 Updated: 2026 Q2
⚠️

PFAS above the federal limit at 2 of 4 sampling points

Lead is 2.40 ppb, 16% of the action level and no violations are open. However, PFAS exceeds the federal limit at 2 of 4 sampling points, running as high as 2.13 times the limit.

C

Rib Mountain earns a C for water quality

Graded on violations, lead, and PFAS, with state inspection findings.

Lead: 2.40 ppb — 16% of the federal action level
PFAS above the federal limit at 2 of 4 sampling points
2 violations since 2015, 0 health-based
No violations currently open
Rib Mountain's lead level vs. all Wisconsin community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: 2.40 ppb — 16% of the federal action level
✓ Lower lead than 45% of Wisconsin utilities
Population Served
4463
~2416 connections
Water Source
Groundwater
Drawn from wells — SDWIS source code GW
Active Violations
0
2 since 2015, all resolved

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
16% of EPA action level
2.40 ppb
Action level: 15 ppb
The 90th-percentile lead result is 2.40 ppb, 16% of the 15 ppb federal action level. The action level is a treatment trigger, not a legal maximum, and it is measured across sampled taps rather than at any single home.

Contaminant Violations (2015–Present)

ContaminantTypeMeasuredLimitPeriodStatus
Total Haloacetic Acids (HAA5) MONITORING AND REPORTING — 0.060 mg/L 2018 Resolved
TTHM MONITORING AND REPORTING — 0.080 mg/L 2018 Resolved
Understanding violation types MCL violations mean a contaminant exceeded the federal maximum limit — the most serious type.
TT (Treatment Technique) violations mean required treatment procedures weren't followed, but don't necessarily mean contamination occurred.

Violation History

2 violations are on record since 2015, of which 0 were health-based. All have been resolved and none remain open.

About the Main Water System

Utility Rib Mountain Water Utility
PWSID WI7370660
Water source Groundwater — Drawn from wells — SDWIS source code GW
Population served 4,463
Service connections 2,416
Systems serving this area 2
Regulator State primacy agency
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Rib Mountain tap water safe to drink? ▼
It meets most federal standards, but PFAS exceeds the federal limit at 2 of 4 sampling points. No violations are currently open. Lead is 2.40 ppb, 16% of the action level.
Does Rib Mountain water have PFAS? ▼
Yes. PFAS exceeds the federal limit at 2 of 4 sampling points, running as high as 2.13 times the limit. Limits are enforced on a running annual average at each sampling point, not on a single sample.
Who supplies water to Rib Mountain? ▼
Rib Mountain Water Utility (PWSID WI7370660), one of 2 systems serving this area. Groundwater. Drawn from wells — SDWIS source code GW
When was this system last inspected? ▼
It was last inspected on 2023-04-25. No significant deficiencies were recorded.

What Should Rib Mountain Residents Do?

1
Consider a reverse-osmosis filter
Reverse osmosis removes more than 95% of PFAS. Standard carbon pitchers do not.
2
Check for a lead service line
Lead reaches tap water mainly through service lines and household plumbing. Suppliers now publish an inventory identifying lead lines.
3
Flush before drinking
If water has sat in pipes more than six hours, run the cold tap for two minutes before drinking or cooking.

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