Yankton
EPA ID: SD4600423 · 15,411 people served · 1 ZIP code
ZipCheckup's reading of EPA records for Yankton (SD4600423): no drinking-water violations recorded since 2021. Federal monitoring records show zero violations at Yankton for the reporting cycles they cover, at a utility serving approximately 15,411 residents.
Data: EPA SDWIS
Service Area Map
Coverage area for Yankton Source: EPA SDWIS service area boundaries.
Service area boundary
Demographics of ZIP Codes Served
The ZIP codes associated with Yankton have a median household income of $72,395 and about 20,547 residents live in those ZIP codes (Census; not the number of people this system supplies). Approximately 62% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: On average, 40% of census tracts in the counties mapped to this service area are designated disadvantaged by the federal Climate and Economic Justice Screening Tool (CEJST, 2022 version). 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 classified in EPA records as a groundwater source. 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.
Wastewater Proximity Note: This service area ranks in the 80th percentile nationally for proximity to wastewater discharge points.
Infrastructure Risk
Comparable Water Systems
Similar-sized systems in South Dakota
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.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| Below the reporting limit | No | 2024-12-31 |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
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: Ask your water utility whether running cold water for 2 minutes is enough to flush your plumbing before drinking.
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 available EPA compliance records for Yankton (SD4600423) on EPA.gov.
Frequently Asked Questions
Is Yankton water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Yankton in the inclusive 2021-2026 record-year window. This is a compliance-record finding, not a guarantee about water at a specific tap.
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: No PFAS Reported Above Reporting Levels
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). No PFAS compounds were reported above UCMR5 minimum reporting levels.
EPA's April 2024 PFAS rule sets MCLs of 4 ppt for PFOA and PFOS and 10 ppt for PFHxS, PFNA and HFPO-DA (GenX); water systems must comply from 2029. Other PFAS compounds have no individual federal MCL. A state standard is shown only where this system's state has its own enforceable PFAS limit. Detection results are EPA UCMR5 samples, not a measurement at your tap.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
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
How to cite this page
ZipCheckup. (n.d.). Yankton, SD: Serves 15K People. https://zipcheckup.com/water-system/sd4600423/
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title = {{Yankton, SD: Serves 15K People}},
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url = {https://zipcheckup.com/water-system/sd4600423/}
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