Community Water System · PWS MO6010657
Portage Des Sioux PWS
Portage Des Sioux, Missouri 63373-0000 - drinking water served from groundwater sources to 345 people, tracked in EPA SDWIS and UCMR5.
- 345
- People served
- 115
- EPA violations
- 10
- Health-based
- Untested
- UCMR5 result
The verdict
EPA records 115 drinking-water violations at Portage Des Sioux PWS, 9% of them health-based - above the Missouri per-system average.
- 115
- Total EPA violations on record
- 9%
- Health-based (MCL / treatment failure)
- 345
- People served by this system
- N/A
- PFAS compounds detected (UCMR5)
Water Quality Snapshot: Portage Des Sioux PWS
Portage Des Sioux PWS is a local-owned community water system that delivers drinking water to 345 residents in Portage Des Sioux, Missouri (St. Charles County) through 165 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 115 total violations for this system , of which 10 (9%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 97 monitoring and reporting violations are on file. The most recent violation on record dates to 2019.
The most frequently cited contaminant at this system is Coliform (TCR), recorded in 53 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.
Across Missouri, EPA tracks 2,823 public water systems serving 5,855,885 people, with 201,695 cumulative violations and 54,821 health-based violations on record. About 95% of systems in the state carry at least one violation, and state-wide the average per system is 71.4 violations. Statewide, 162 of 230 UCMR5-tested systems have reported PFAS detections (70.4%).
Portage Des Sioux PWS's 115 violations sit above the Missouri 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
- 165
- County
- St. Charles
- School/Daycare
- No
- MCL Violations
- 6
- Monitoring Violations
- 97
- Treatment Tech Violations
- 4
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 53 | 2014 |
| Revised Total Coliform Rule | MON | 8 | 2019 |
| Coliform (TCR) | MCL | 6 | 1996 |
| Groundwater Rule | TT | 4 | 2015 |
| Lead and Copper Rule | MR | 3 | 2003 |
| Mercury | MR | 2 | 1996 |
| Consumer Confidence Rule | Other | 2 | 2019 |
| Public Notice | Other | 1 | 2016 |
| Trichloroethylene | MR | 1 | 1996 |
| Carbon tetrachloride | MR | 1 | 1996 |
| o-Dichlorobenzene | MR | 1 | 1996 |
| Cadmium | MR | 1 | 1996 |
| CYANIDE | MR | 1 | 1996 |
| Barium | MR | 1 | 1996 |
| cis-1,2-Dichloroethylene | MR | 1 | 1996 |
| 1,2-Dichloropropane | MR | 1 | 1996 |
| 1,1-Dichloroethylene | MR | 1 | 1996 |
| Fluoride | MR | 1 | 1996 |
| 1,1,1-Trichloroethane | MR | 1 | 1996 |
| Tetrachloroethylene | MR | 1 | 1996 |
| p-Dichlorobenzene | MR | 1 | 1996 |
| Selenium | MR | 1 | 1996 |
| DICHLOROMETHANE | MR | 1 | 1996 |
| Antimony, Total | MR | 1 | 1996 |
| Ethylbenzene | MR | 1 | 1996 |
| Xylenes, Total | MR | 1 | 1996 |
| 1,2-Dichloroethane | MR | 1 | 1996 |
| 1,1,2-Trichloroethane | MR | 1 | 1996 |
| Beryllium, Total | MR | 1 | 1996 |
| Toluene | MR | 1 | 1996 |
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 Portage Des Sioux PWS.
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 MO6010657 on SDWISSource: EPA SDWIS Federal Reports Search
Missouri Drinking Water Authority
Missouri DNR, Public Drinking Water Branch is the primacy agency that licenses and inspects Portage Des Sioux PWS under EPA-delegated authority.
Open MO regulator portalViolation 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 |
|---|---|---|---|---|
| 2019 | Revised Total Coliform Rule | MON | 8 | SDWIS / MO6010657 / 8000 |
| 2019 | Consumer Confidence Rule | Other | 2 | SDWIS / MO6010657 / 7000 |
| 2016 | Public Notice | Other | 1 | SDWIS / MO6010657 / 7500 |
| 2015 | Groundwater Rule | TT | 4 | SDWIS / MO6010657 / 0700 |
| 2014 | Coliform (TCR) | MR | 53 | SDWIS / MO6010657 / 3100 |
| 2003 | Lead and Copper Rule | MR | 3 | SDWIS / MO6010657 / 5000 |
| 1996 | Coliform (TCR) | MCL | 6 | SDWIS / MO6010657 / 3100 |
| 1996 | Mercury | MR | 2 | SDWIS / MO6010657 / 1035 |
| 1996 | Trichloroethylene | MR | 1 | SDWIS / MO6010657 / 2984 |
| 1996 | Carbon tetrachloride | MR | 1 | SDWIS / MO6010657 / 2982 |
| 1996 | o-Dichlorobenzene | MR | 1 | SDWIS / MO6010657 / 2968 |
| 1996 | Cadmium | MR | 1 | SDWIS / MO6010657 / 1015 |
| 1996 | CYANIDE | MR | 1 | SDWIS / MO6010657 / 1024 |
| 1996 | Barium | MR | 1 | SDWIS / MO6010657 / 1010 |
| 1996 | cis-1,2-Dichloroethylene | MR | 1 | SDWIS / MO6010657 / 2380 |
How Portage Des Sioux PWS Compares
Cross-reference this system's record against state averages and the federal MCL framework for context.
| Metric | Portage Des Sioux PWS | Missouri avg | Federal benchmark |
|---|---|---|---|
| Total violations | 115 | 71.4 | SDWA compliance, any non-zero count is a recorded breach |
| Health-based violations | 10 | 19.4 | Indicates a contaminant exceeded a federal MCL |
| PFAS detection | None | 70.4% | EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt |
| Population served | 345 | 2,074 | Sizing context for compliance burden |
Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 2,823 regulated public water systems in Missouri.
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 Portage Des Sioux PWS water safe to drink? ▼
How many people does Portage Des Sioux PWS serve? ▼
What type of violations does Portage Des Sioux PWS have? ▼
Has PFAS been detected in Portage Des Sioux PWS water? ▼
What water source does Portage Des Sioux PWS 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.