Public water system · IA6000755
ActiveLyon-Sioux Rws-Big Sioux
At a glance
Lyon-Sioux Rws-Big Sioux (PWSID IA6000755) is an active community water system in Lyon County, Iowa. It reports serving 1,530 people through 612 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in October 2019.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,530
Service connections
612
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Lyon-Sioux Rws-Big Sioux compare with other water systems in Lyon County?
By EPA's size categories, Lyon-Sioux Rws-Big Sioux is a small system (501 to 3,300 people). Lyon County has 12 active public water systems, and Lyon-Sioux Rws-Big Sioux is the 3rd-largest of them by population served. Its population served is about 51% above the county average of 1,016 people per system, and accounts for 13% 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-Big Sioux 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-Big Sioux?
EPA lists Lyon-Sioux Rws-Big Sioux 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-Big Sioux have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in October 2019. The violations listed here began between January 2005 and October 2019. By type: 12 monitoring and reporting. The contaminants or rules involved are Nitrite, Combined Radium (-226 and -228), Nitrate and Barium. EPA lists 12 as resolved. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2019-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitritecode 1041 | No | Resolved |
| 2012-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Resolved |
| 2010-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Bariumcode 1010 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Cadmiumcode 1015 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chromiumcode 1020 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Mercurycode 1035 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Antimonycode 1074 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Arseniccode 1005 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Thalliumcode 1085 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Fluoridecode 1025 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Seleniumcode 1045 | No | Resolved |
The 12 most recent 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-Big Sioux: frequently asked questions
Who runs Lyon-Sioux Rws-Big Sioux?
Lyon-Sioux Rws-Big Sioux (PWSID IA6000755) is a community water system privately owned. It is regulated by the IA state drinking water program.
How many people does Lyon-Sioux Rws-Big Sioux serve?
Lyon-Sioux Rws-Big Sioux reports serving 1,530 people through 612 service connections in Lyon County, Iowa.
Where does Lyon-Sioux Rws-Big Sioux 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-Big Sioux have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in October 2019. 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-Big Sioux'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. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in October 2019. 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-Big Sioux's water quality report?
As a community water system, Lyon-Sioux Rws-Big Sioux 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-Doon | Lyon | 1,765 | 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 |
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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-Big Sioux, PWSID IA6000755, Iowa”, https://aquacensus.com/water-systems/iowa/lyon-sioux-rws-big-sioux-ia6000755 (data as of October 1, 2026).