Mequon-Thiensville School District (WI): 3 Health Violations
3 ZIP codes · 15 water systems · 637,282 people served · Updated 2026-06-26
Data: EPA SDWIS, NCES Last verified: 2026-06-26
Why School Water Quality Matters
Children drink 2–4× more water per pound of body weight than adults, making them more vulnerable to contaminants. School water quality affects students for hours every weekday.
Water Quality Overview
The Mequon-Thiensville School District in Wisconsin spans 3 ZIP codes served by 15 community water systems, providing water to approximately 637,282 people.
The average Home Safety Score across the district is C (68/100) — with the lowest-scoring area at 65/100 .
Water quality in this district falls in the bottom 51% nationally.
Why This Matters for Children
Children are more vulnerable to water contaminants than adults. The EPA and CDC identify these key risks:
- Lead exposure — Even low levels of lead can affect brain development, reduce IQ, and cause behavioral problems in children. There is no safe level of lead for children.
- PFAS ("forever chemicals") — Linked to immune system effects and developmental delays in children. Children drink more water relative to body weight than adults.
- Nitrate — Dangerous for infants (can cause "blue baby syndrome"). Agricultural areas often have elevated nitrate.
- Disinfection byproducts — Long-term exposure may increase cancer risk. School water fountains often have stagnant water that concentrates these compounds.
Lead Levels in the District
| Metric | Value | EPA Threshold |
|---|---|---|
| Average lead level (90th percentile) | 0.0021 mg/L | 0.015 mg/L |
| Highest lead level | 0.0053 mg/L | 0.015 mg/L |
| ZIP codes exceeding EPA action level | 0 of 3 | — |
EPA Violation History
Contaminants of Concern
| Contaminant | Category | Violations | Health-Based | ZIPs Affected |
|---|---|---|---|---|
| Consumer Confidence Report Rule | Reporting | 15 | No | 1 |
| Lead and Copper Rule | Treatment Technique | 9 | No | 2 |
| Stage 2 DBP Rule | Treatment Technique | 8 | Yes | 3 |
| Surface Water Treatment Rule | Treatment Technique | 6 | No | 1 |
| Stage 1 DBP Rule | Treatment Technique | 3 | No | 1 |
| Total Coliform | Microbiological | 2 | No | 1 |
| Lead | Inorganic | 1 | No | 1 |
| Contaminant 2356 | Other | 1 | No | 1 |
Radon Risk
Dominant radon zone: Zone 2 (Moderate risk)
Water Quality by ZIP Code
| ZIP Code | City | Safety Score | Violations | Health | Lead Level | Exceeds? |
|---|---|---|---|---|---|---|
| 53217 | Milwaukee | C (65) | 41 | 2 | 0.0053 mg/L | No |
| 53097 | Mequon | B (74) | 5 | 1 | 0.00052 mg/L | No |
| 53092 | Thiensville | C (66) | 1 | 0 | 0.000493 mg/L | No |
What Parents Can Do
- Request lead testing at your child's school — The EPA's 3Ts program (Training, Testing, Taking Action) provides guidance for schools. Ask your school board about their water testing schedule.
- Review the Consumer Confidence Report (CCR) — Your water utility publishes this annually. It details all detected contaminants.
- Test your home's water — Especially if your home has older plumbing (pre-1986) that may contain lead solder or lead pipes.
- Pack water from home — If you're concerned about school water quality, send your child with a water bottle filled at home (filtered if possible).
- Stay informed — Bookmark this page to check for updates on water quality in your school district.
Need help with school water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
Frequently Asked Questions
Is the water safe in Mequon-Thiensville School District schools?
Water systems serving Mequon-Thiensville School District have recorded 3 health-based violations in the past 5 years. While utilities are required to meet federal standards, individual school buildings may have older plumbing that can introduce contaminants. Parents should request lead testing results from their school.
Does Mequon-Thiensville School District test for lead in school water?
Federal law does not require schools to test for lead in drinking water (except in some states with specific mandates). The EPA's voluntary 3Ts program encourages testing. Contact your school district office to ask about their testing schedule and results.
What level of lead is safe for children?
There is no safe level of lead for children, according to the CDC. The EPA action level of 0.015 mg/L (15 ppb) triggers corrective action for water systems, but the American Academy of Pediatrics recommends that school water contain no more than 0.001 mg/L (1 ppb).
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- School districts: NCES EDGE Geographic Relationship Files
- Radon: EPA Map of Radon Zones
Updated daily.