Sioux City Water Supply
EPA ID: IA9778054 · 85,791 people served · 11 ZIP codes
A total of 2 EPA violations spanning the past five monitoring years sit on Sioux City Water Supply's record — every finding has been officially cleared, and the supplier now holds current compliance status for its service population of approximately 85,791 people, with no outstanding enforcement of any kind.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Sioux City Water Supply Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The Sioux City Water Supply serves a community with a median household income of $72,618 and an estimated 96,763 residents across its service area. Approximately 78% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
🌊 Where Does Your Water Come From?
Sioux City Water Supply'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 Woodbury 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 Sioux City Water Supply compares to EPA limits
What This Means For You
Haloacetic Acids (HAA5) at 1 mg/L exceeds the EPA maximum of 0.06 mg/L. Cancer risk; reproductive & developmental effects. Consider granular activated carbon (GAC) filtration.
Consumer Confidence Report Rule at 2 mg/L exceeds the EPA maximum of mg/L.
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 72 detections recorded. 24 exceed federal EPA limits (4 ppt for PFOA/PFOS).
Haloacetic Acids (HAA5) was detected in this water system. granular activated carbon (GAC) filtration can reduce exposure.
Find a certified water filter →Comparable Water Systems
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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
Sioux City Water Supply (EPA ID: IA9778054) is a community water system in Iowa that serves approximately 85,791 people from surface water sources.
This system provides water to 11 ZIP codes across 3 communities.
Average Home Safety Score: C (67/100)
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 |
|---|---|---|---|
| May 1, 2024 | Haloacetic Acids (HAA5) | Monitoring | Resolved |
| June 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 |
|---|---|---|---|
| Consumer Confidence Report Rule | Reporting Failure | 2 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 1 | 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 |
|---|---|---|---|
| 51030 | 0.0043 mg/L | No | N/A |
| 51101 | 0.002 mg/L | No | N/A |
| 51102 | 0.002 mg/L | No | N/A |
| 51103 | 0.002 mg/L | No | N/A |
| 51104 | 0.002 mg/L | No | N/A |
| 51105 | 0.002 mg/L | No | N/A |
| 51106 | 0.002 mg/L | No | N/A |
| 51108 | 0.002 mg/L | No | N/A |
| 51109 | 0.002 mg/L | No | N/A |
| 51111 | 0.002 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
Coverage: 9 ZIP codes confirmed via EPA Community Water System Service Area Boundaries v3 plus 2 additional ZIPs inferred from SDWIS registry data. The EPA-confirmed set is the most reliable; SDWIS-inferred entries may be narrower than the real deployment area.
- 51030 — Lawton
- 51054 — Sergeant Bluff
- 51101 — Sioux City
- 51102 — Sioux City
- 51103 — Sioux City
- 51104 — Sioux City
- 51105 — Sioux City
- 51106 — Sioux City
- 51108 — Sioux City
- 51109 — Sioux City
- 51111 — Sioux City
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Sioux City Water Supply (IA9778054) on EPA.gov.
Frequently Asked Questions
Is Sioux City Water Supply water safe to drink?
Sioux City Water Supply has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
How many people does Sioux City Water Supply serve?
Sioux City Water Supply serves approximately 85,791 people across 11 ZIP codes in Iowa.
Where does Sioux City Water Supply get its water?
The primary water source is surface water.
Federal UCMR5 PFAS Monitoring: Above Current MCL
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). One or more PFAS compounds were measured above the current state-enforceable MCL.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
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.
How Water Systems Appear in Rankings
Water systems are evaluated by violation history, contaminant detections, and service population. Larger systems with more service connections appear in more rankings.
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
Sioux City Water Supply (EPA ID: IA9778054) — request the latest Consumer Confidence Report or ask about specific contaminants.