Diagonal Water Department
EPA ID: IA8018040 · 338 people served · 4 ZIP codes
Diagonal Water Department carries 2 open EPA violations that remain unresolved in the federal system — approximately 338 people fall within its service area.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Diagonal Water Department Source: EPA SDWIS service area boundaries.
Service area boundary — Grade D
Service Area Demographics
The Diagonal Water Department serves a community with a median household income of $68,932 and an estimated 1,294 residents across its service area. Approximately 77% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
🌊 Where Does Your Water Come From?
Diagonal Water Department's water is drawn from rivers, lakes, or reservoirs. Surface water sources are more exposed to agricultural runoff, stormwater, and upstream discharges, but they typically receive more intensive treatment before reaching your tap.
About 2% of homes in Union County, Iowa rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Infrastructure Risk
Detected Contaminants
How Diagonal Water Department compares to EPA limits
What This Means For You
Consumer Confidence Report Rule at 3 mg/L exceeds the EPA maximum of mg/L.
Copper at 3 mg/L exceeds the EPA maximum of 1.3 mg/L.
Lead and Copper Rule at 2 mg/L exceeds the EPA maximum of mg/L.
Comparable Water Systems
Similar-sized systems in Iowa
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
DIAGONAL WATER DEPARTMENT (EPA ID: IA8018040) is a community water system in Iowa that serves approximately 338 people from surface water sources.
This system provides water to 4 ZIP codes across 4 communities.
Average Home Safety Score: D (45/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| March 21, 2025 | Lead and Copper Rule | Monitoring | Unresolved |
| October 21, 2024 | Lead and Copper Rule | Monitoring | Unresolved |
| October 1, 2024 | Copper | Monitoring | Resolved |
| October 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| April 1, 2024 | Copper | Monitoring | Resolved |
| January 1, 2024 | Copper | Monitoring | Resolved |
| April 1, 2023 | Consumer Confidence Report Rule | Monitoring | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Copper | Inorganic | 3 | No |
| Consumer Confidence Report Rule | Reporting Failure | 3 | No |
| Lead and Copper Rule | Treatment Failure | 2 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 50845 | 0.0016 mg/L | No | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Need help with your 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.
ZIP Codes Served
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Diagonal Water Department (IA8018040) on EPA.gov.
Frequently Asked Questions
Is Diagonal Water Department water safe to drink?
Diagonal Water Department has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
How many people does Diagonal Water Department serve?
Diagonal Water Department serves approximately 338 people across 4 ZIP codes in Iowa.
Where does Diagonal Water Department get its water?
The primary water source is surface water.
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
This system reports zero confirmed lead service lines in its inventory. Unknown-material counts may still warrant verification.
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.
Frequently Asked Questions
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Diagonal Water Department (EPA ID: IA8018040) — request the latest Consumer Confidence Report or ask about specific contaminants.