Community Water System · PWS SD4600220
Mount Vernon
Mount Vernon, South Dakota 57363 - drinking water served from surface water sources to 461 people, tracked in EPA SDWIS and UCMR5.
- 461
- People served
- 39
- EPA violations
- 17
- Health-based
- Untested
- UCMR5 result
The verdict
EPA records 39 drinking-water violations at Mount Vernon, 44% of them health-based - below the South Dakota per-system average.
- 39
- Total EPA violations on record
- 44%
- Health-based (MCL / treatment failure)
- 461
- People served by this system
- N/A
- PFAS compounds detected (UCMR5)
Water Quality Snapshot: Mount Vernon
Mount Vernon is a local-owned community water system that delivers drinking water to 461 residents in Mount Vernon, South Dakota (Davison County) through 204 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 39 total violations for this system , of which 17 (44%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 16 monitoring and reporting violations are on file. The most recent violation on record dates to 2020.
The most frequently cited contaminant at this system is Coliform (TCR), recorded in 15 violations (MCL, health-based). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.
Across South Dakota, EPA tracks 654 public water systems serving 915,901 people, with 56,254 cumulative violations and 8,399 health-based violations on record. About 92% of systems in the state carry at least one violation, and state-wide the average per system is 86 violations. Statewide, 42 of 49 UCMR5-tested systems have reported PFAS detections (85.7%).
Mount Vernon's 39 violations sit below the South Dakota average.
All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 204
- County
- Davison
- School/Daycare
- No
- MCL Violations
- 15
- Monitoring Violations
- 16
- Treatment Tech Violations
- 2
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 15 | 1995 |
| Coliform (TCR) | MR | 14 | 1996 |
| Stage 1 Disinfectants and Disinfection Byproducts Rule | TT | 2 | 2020 |
| Combined Radium (-226 and -228) | MR | 1 | 1976 |
| Gross Alpha, Excl. Radon and U | MR | 1 | 1976 |
Verify This Water System
The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Mount Vernon.
EPA SDWIS, Federal Reports
EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:
View PWS ID SD4600220 on SDWISSource: EPA SDWIS Federal Reports Search
South Dakota Drinking Water Authority
South Dakota's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.
Find SD regulator via EPA SDWISViolation Timeline
Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.
| Year (latest) | Contaminant | Category | Count | EPA Record |
|---|---|---|---|---|
| 2020 | Stage 1 Disinfectants and Disinfection Byproducts Rule | TT | 2 | SDWIS / SD4600220 / 0400 |
| 1996 | Coliform (TCR) | MR | 14 | SDWIS / SD4600220 / 3100 |
| 1995 | Coliform (TCR) | MCL | 15 | SDWIS / SD4600220 / 3100 |
| 1976 | Combined Radium (-226 and -228) | MR | 1 | SDWIS / SD4600220 / 4010 |
| 1976 | Gross Alpha, Excl. Radon and U | MR | 1 | SDWIS / SD4600220 / 4000 |
How Mount Vernon Compares
Cross-reference this system's record against state averages and the federal MCL framework for context.
| Metric | Mount Vernon | South Dakota avg | Federal benchmark |
|---|---|---|---|
| Total violations | 39 | 86 | SDWA compliance, any non-zero count is a recorded breach |
| Health-based violations | 17 | 12.8 | Indicates a contaminant exceeded a federal MCL |
| PFAS detection | None | 85.7% | EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt |
| Population served | 461 | 1,400 | Sizing context for compliance burden |
Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 654 regulated public water systems in South Dakota.
Federal MCL reference, Safe Drinking Water Act thresholds ▼
| Contaminant | Federal MCL / Action Level | Note |
|---|---|---|
| Lead | 0 mg/L (Action Level: 0.015 mg/L) | Lead and Copper Rule treatment technique |
| Arsenic | 0.010 mg/L (10 ppb) | Health-based MCL since 2006 |
| Total Coliform | Treatment technique (RTCR) | Indicator organism, monitoring trigger |
| PFOA / PFOS (PFAS) | 4.0 ppt each (final 2024 rule) | Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026) |
| Nitrate (as N) | 10 mg/L | Acute health risk for infants |
Frequently Asked Questions
Is Mount Vernon water safe to drink? ▼
How many people does Mount Vernon serve? ▼
What type of violations does Mount Vernon have? ▼
Has PFAS been detected in Mount Vernon water? ▼
What water source does Mount Vernon use? ▼
Where does this data come from? ▼
Read our methodology - how this data is sourced, computed, and verified.
Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.