Community Water System · PWS WI7370159
Mosinee Waterworks
Operator location Mosinee, Wisconsin - 25% of 28 violations are health-based (upper-third health share (> 23%)); groundwater source; 3,406 served per SDWIS.
- 3,406
- People served (this PWS)
- 28
- EPA violations (this PWS)
- 7
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Mosinee Waterworks standing, mid SDWIS violation third
25% of 28 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 25% is upper-third health share (> 23%). Population rank #9,791 of 29,740 among systems serving 500+.
The verdict
Mosinee Waterworks lands in the middle third by violation volume (28), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is large (3,406; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 25% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.
- #9,791 of 29,740
- Population · /systems
- #186 of 744
- Population · WI
- 28
- Total EPA violations on record
- 25%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 1,783
- County
- Marathon
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 13
- Treatment Tech Violations
- 7
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Lead and Copper Rule | MR | 9 | 2017 |
| Lead and Copper Rule | TT | 6 | 2013 |
| Public Notice | Other | 5 | 2024 |
| Bromate | MR | 4 | 2005 |
| LEAD AND COPPER RULE REVISIONS | TT | 1 | 2024 |
Violation Count vs. the National Corpus
Mosinee Waterworks has 28 recorded EPA violations, 40% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 59% carry more. 25% of this system's own violations are health-based (7 of 28), and it ranks #9,791 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
28 Lower than most fewer violations than 59% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
Health-based violations on Mosinee Waterworks
7 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for WI7370159.
Sources: EPA SDWIS · Wisconsin DNR, Drinking Water and Groundwater
Nationwide peers
28 violations · 3,406 served: nearest cross-state SDWIS matches.
Cross-state systems near this violation count
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems with similar served population
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Mosinee Waterworks
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Wisconsin compares on the same EPA violation measures. Wisconsin systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.