Public water system · IA6000733
ActiveLyon-Sioux Rws-Doon
At a glance
Lyon-Sioux Rws-Doon (PWSID IA6000733) is an active community water system in Lyon County, Iowa. It reports serving 1,765 people through 706 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in July 2018.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,765
Service connections
706
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Lyon-Sioux Rws-Doon compare with other water systems in Lyon County?
By EPA's size categories, Lyon-Sioux Rws-Doon is a small system (501 to 3,300 people). Lyon County has 12 active public water systems, and Lyon-Sioux Rws-Doon is the 2nd-largest of them by population served. Its population served is about 74% above the county average of 1,016 people per system, and accounts for 14% of the 12,196 people reported by systems filed under the county. Across Iowa, the 1,828 active systems average 1,718 people each. Nationally, the average active community water system reports serving 6,703 people, so Lyon-Sioux Rws-Doon is well below that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Iowa has 1,084 active community water systems, 59% of the state's 1,828 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,502 Iowa systems (82%) list groundwater as their primary source.
Who owns and regulates Lyon-Sioux Rws-Doon?
EPA lists Lyon-Sioux Rws-Doon as privately owned. The IA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 4 of the 12 active systems in Lyon County (33%) are also privately owned.
Does Lyon-Sioux Rws-Doon have drinking water violations?
EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in July 2018. The violations listed here began between October 1983 and July 2018. By type: 3 contaminant level above the legal limit and 2 monitoring and reporting. The contaminant or rule involved most often is Nitrate (5 of them). EPA lists 3 as resolved and 2 as archived. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2018-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1997-12-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1994-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 1984-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Archived |
| 1983-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Archived |
All 5 violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Lyon-Sioux Rws-Doon: frequently asked questions
Who runs Lyon-Sioux Rws-Doon?
Lyon-Sioux Rws-Doon (PWSID IA6000733) is a community water system privately owned. It is regulated by the IA state drinking water program.
How many people does Lyon-Sioux Rws-Doon serve?
Lyon-Sioux Rws-Doon reports serving 1,765 people through 706 service connections in Lyon County, Iowa.
Where does Lyon-Sioux Rws-Doon get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Lyon-Sioux Rws-Doon have any drinking water violations?
EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in July 2018. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Lyon-Sioux Rws-Doon's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in July 2018. For current results, consult the system's annual water quality report, EPA ECHO, or the IA state drinking water program.
Where can I find Lyon-Sioux Rws-Doon's water quality report?
As a community water system, Lyon-Sioux Rws-Doon must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in Lyon County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Rock Rapids Municipal Water Works | Lyon | 2,611 | Community | Groundwater |
| Lyon-Sioux Rws-Big Sioux | Lyon | 1,530 | Community | Groundwater |
| Lyon-Sioux Rws-Rock Rapids | Lyon | 1,187 | Community | Purchased groundwater |
| George Water Supply | Lyon | 1,082 | Community | Groundwater |
| Inwood Water Supply | Lyon | 928 | Community | Purchased groundwater |
| Larchwood Water Supply | Lyon | 926 | Community | Purchased groundwater |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Lyon-Sioux Rws-Doon, PWSID IA6000733, Iowa”, https://aquacensus.com/water-systems/iowa/lyon-sioux-rws-doon-ia6000733 (data as of October 1, 2026).