Yankton
EPA ID: SD4600423 · 15,411 people served · 1 ZIP code
Looking at the EPA enforcement file for Yankton, 3 violations are listed as unresolved — those findings cover the utility's service area of approximately 15,411 people and remain open in the federal compliance system, awaiting formal corrective action documentation.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Yankton Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The Yankton serves a community with a median household income of $72,395 and an estimated 20,547 residents across its service area. Approximately 62% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 40% of the population in this service area is classified as disadvantaged under EPA's EJScreen criteria. Communities with higher disadvantaged populations often face disproportionate environmental and health burdens, including aging water infrastructure and limited resources for remediation.
💧 Where Does Your Water Come From?
Yankton'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 1% of homes in Yankton County, South Dakota rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Wastewater Proximity Note: This service area ranks in the 80th percentile nationally for proximity to wastewater discharge points.
Infrastructure Risk
Detected Contaminants
How Yankton compares to EPA limits
What This Means For You
Revised Total Coliform Rule at 2 presence exceeds the EPA maximum of presence.
Consumer Confidence Report Rule at 1 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
Yankton (EPA ID: SD4600423) is a community water system in South Dakota that serves approximately 15,411 people from groundwater sources.
This system serves ZIP code 57078 in Yankton.
Average Home Safety Score: C (64/100)
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 |
|---|---|---|---|
| February 1, 2025 | Chlorine residual | Health-based | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Revised Total Coliform Rule | Microbiological | 2 | No |
| Consumer Confidence Report Rule | Reporting Failure | 1 | 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:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 57078 | 0.001 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: 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.
- 57078 — Yankton
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Yankton (SD4600423) on EPA.gov.
Frequently Asked Questions
Is Yankton water safe to drink?
Yankton 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 Yankton serve?
Yankton serves approximately 15,411 people across 1 ZIP code in South Dakota.
Where does Yankton 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
Yankton (EPA ID: SD4600423) — request the latest Consumer Confidence Report or ask about specific contaminants.