Water Quality in Delavan, WI: 69 Violations Recorded for Mapped Water Systems
5 water systems · 1 directly mapped ZIP records
Available EPA records report 69 violations across 1 directly mapped ZIP records with known counts for Delavan. This is compliance evidence, not a property-level tap-water verdict.
Data: EPA Safe Drinking Water Information System (SDWIS)
Water Quality by ZIP Code in Delavan
This table shows typed EPA water evidence only. Missing violation counts are displayed as N/A, not zero.
| ZIP Code | Violations | Health | |
|---|---|---|---|
| 53115 | 69 | 2 | View report → |
Water Quality Overview
Delavan, Wisconsin has directly mapped EPA water-system data for 1 ZIP codes. This page reports typed compliance facts and does not relabel the multi-source Home Safety Score as a drinking-water grade.
The available EPA records report 69 violations, including 2 health-based violations across 1 directly mapped ZIP record with reported counts.
Lead Levels
The average of the reported 90th-percentile lead results across the ZIP codes of Delavan is 0.0100 mg/L; the EPA action level of 0.015 mg/L applies to a water system's own 90th-percentile result and is not a safety threshold (EPA's health goal for lead is zero). No exceedances appear among the 1 ZIP records with known lead status.
With 63% of homes built before 1986, Delavan has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Water Systems Serving Delavan
Delavan is served by 5 community water systems regulated under the Safe Drinking Water Act. About 16,056 people live in the area (1 ZIP code, Census); this is not the systems' reported service population.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
EPA records list enforcement actions against water systems serving Delavan. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Delavan
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels and violation history
Request your CCR - your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test - certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration - NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories - monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Delavan Water Systems
The following contaminants have been detected or caused violations across Delavan's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Lead and Copper Rule | Treatment Technique | N/A | 11 | 1 | Yes |
| Consumer Confidence Rule | Reporting | N/A | 4 | 1 | No |
| Nitrate | Inorganic | 10 mg/L | 2 | 1 | No |
| 1,2,4-Trichlorobenzene | Organic | N/A | 2 | 1 | No |
| cis-1,2-Dichloroethylene | Organic | N/A | 2 | 1 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 2 | 1 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 2 | 1 | No |
| Xylenes, Total | Organic | N/A | 2 | 1 | No |
| Dichloromethane | Organic | N/A | 2 | 1 | No |
| o-Dichlorobenzene | Organic | N/A | 2 | 1 | No |
| p-Dichlorobenzene | Organic | N/A | 2 | 1 | No |
| Vinyl chloride | Organic | N/A | 2 | 1 | No |
| 1,1-Dichloroethylene | Organic | N/A | 2 | 1 | No |
| trans-1,2-Dichloroethylene | Organic | N/A | 2 | 1 | No |
| 1,2-Dichloroethane | Organic | N/A | 2 | 1 | No |
The standard column shows the EPA Maximum Contaminant Level (MCL) except for lead and copper, whose value is an action level that triggers corrective steps and is not an MCL. Health-based violations are MCL, MRDL and treatment-technique violations.
Violation Trend Over Time
Year-by-year health-based EPA violations recorded for water systems serving Delavan (this history covers health-based records only):
| Year | Health-based violations |
|---|---|
| 2022 | 1 |
| 2025 | 1 |
Health-based violation counts have remained stable over the observed period.
EPA Enforcement History
The EPA and state regulators have taken enforcement actions against water systems serving Delavan. Recent actions:
| Date | Action Type |
|---|---|
| 2026-02-11 | State Informal Action |
| 2026-02-11 | State Informal Enforcement |
| 2026-01-06 | State Informal Action |
| 2025-12-29 | State Informal Action |
| 2025-12-29 | State Order Extension |
| 2025-11-21 | State Informal Action |
| 2025-11-21 | State Informal Enforcement |
| 2025-11-21 | State Informal Action |
| 2025-11-20 | State Informal Action |
| 2025-11-20 | State Informal Enforcement |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2026-02-11.
Delavan vs. Nearby Wisconsin Cities
How Delavan's water quality compares to similar cities in Wisconsin:
| City | Direct EPA ZIPs | Violations | Systems | Population |
|---|---|---|---|---|
| Delavan | 1 | 69 | 5 | 16,056 |
| Rice Lake | 1 | 23 | 3 | 16,054 |
| Tomah | 1 | 1 | 1 | 16,100 |
| Plymouth | 1 | 4 | 5 | 16,174 |
Common Questions About Delavan Water
These are the most common questions residents search for about water quality in Delavan, Wisconsin:
Is Delavan water hard or soft? Water hardness varies by source. Delavan's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Delavan tap water? City-level EPA records cannot determine safety at a specific tap. The measured subset contains 2 health-based violations; check the affected utility record and consider certified testing.
What is the best water filter for Delavan? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Delavan vs. Wisconsin Average
Understanding how Delavan compares to the broader Wisconsin average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below - water quality can vary significantly even within Delavan.
ZIP Codes in Delavan
Delavan spans 1 ZIP code. EPA water-system coverage is available for 1 directly mapped ZIP code. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Source reporting periods vary. See each cited source for its publication schedule.