Sioux Rural Water System
EPA ID: SD4600866 · 4,012 people served · 14 ZIP codes
Federal data shows 7 unresolved violations at Sioux Rural Water System — roughly 4,012 residents in the service area.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Stable · Risk tier: High · 95% chance of violation in next 12 months
Violations went from 3 (2021) to 1 (2025). Violation counts have remained relatively steady.
Service Area Map
Coverage area for Sioux Rural Water System Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The Sioux Rural Water System serves a community with a median household income of $80,053 and an estimated 38,843 residents across its service area. Approximately 69% 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 Rural Water System's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
About 4% of homes in Codington County, South Dakota 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 Rural Water System compares to EPA limits
What This Means For You
Consumer Confidence Report Rule at 11 mg/L exceeds the EPA maximum of mg/L.
Revised Total Coliform Rule at 5 presence exceeds the EPA maximum of presence.
Stage 1 DBP Rule at 2 mg/L exceeds the EPA maximum of mg/L.
Chlorine residual 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 Rural Water System (EPA ID: SD4600866) is a community water system in South Dakota that serves approximately 4,012 people from groundwater sources.
This system provides water to 14 ZIP codes across 14 communities.
Average Home Safety Score: C (62/100)
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 |
|---|---|---|---|
| July 1, 2025 | Revised Total Coliform Rule | Monitoring | Unresolved |
| May 15, 2025 | Chlorine residual | Health-based | Unresolved |
| May 1, 2025 | Consumer Confidence Report Rule | Monitoring | Resolved |
| April 1, 2025 | Consumer Confidence Report Rule | Monitoring | Resolved |
| April 1, 2025 | Revised Total Coliform Rule | Monitoring | Unresolved |
| March 1, 2025 | Consumer Confidence Report Rule | Monitoring | Resolved |
| February 1, 2025 | Consumer Confidence Report Rule | Monitoring | Resolved |
| January 1, 2025 | Consumer Confidence Report Rule | Monitoring | Resolved |
| December 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| November 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| October 1, 2024 | Stage 1 DBP Rule | Monitoring | Resolved |
| October 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| August 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| June 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| April 1, 2024 | Revised Total Coliform Rule | Monitoring | Unresolved |
| January 1, 2024 | Revised Total Coliform Rule | Monitoring | Unresolved |
| October 1, 2023 | Consumer Confidence Report Rule | Monitoring | Unresolved |
| October 1, 2023 | Stage 1 DBP Rule | Monitoring | Resolved |
| July 1, 2023 | Revised Total Coliform Rule | Monitoring | Unresolved |
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 | 11 | No |
| Revised Total Coliform Rule | Microbiological | 5 | No |
| Stage 1 DBP Rule | Treatment Failure | 2 | No |
| Chlorine residual | Disinfectant | 1 | Yes |
Health Risk Details
Chlorine (Residual Disinfectant) (EPA limit: 4 mg/L (MRDL — Maximum Residual Disinfectant Level))
Irritation & DBP formation at high levels; protective at normal treatment levels At-risk groups: people with asthma or chemical sensitivities, kidney dialysis patients (water must be dechlorinated).
Removal methods: granular activated carbon (GAC), KDF media filter, carbon block filter. Find the right filter →
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
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: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by SD or modeled from parcel and building-footprint data.
- 57201 — Watertown
- 57212 — Arlington
- 57221 — Bryant
- 57223 — Castlewood
- 57226 — Clear Lake
- 57234 — Estelline
- 57235 — Florence
- 57238 — Goodwin
- 57241 — Hayti
- 57242 — Hazel
- 57243 — Henry
- 57248 — Lake Norden
- 57263 — South Shore
- 57271 — Vienna
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Sioux Rural Water System (SD4600866) on EPA.gov.
Frequently Asked Questions
Is Sioux Rural Water System water safe to drink?
Sioux Rural Water System has recorded 1 health-based violation in the past 5 years. While the system is required to treat water to meet federal standards, you may want to consider additional precautions such as a certified water filter.
How many people does Sioux Rural Water System serve?
Sioux Rural Water System serves approximately 4,012 people across 14 ZIP codes in South Dakota.
Where does Sioux Rural Water System get its water?
The primary water source is groundwater.
Federal UCMR5 PFAS Monitoring: Tested Clean
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). No PFAS compounds were detected.
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:
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.
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 Rural Water System (EPA ID: SD4600866) — request the latest Consumer Confidence Report or ask about specific contaminants.