Public water system · IA8482096
ActiveRock Valley Water Supply
At a glance
Rock Valley Water Supply (PWSID IA8482096) is an active community water system in Sioux County, Iowa. It reports serving 4,059 people through 1,866 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in August 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
4,059
Service connections
1,866
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Rock Valley Water Supply compare with other water systems in Sioux County?
By EPA's size categories, Rock Valley Water Supply is a medium system (3,301 to 10,000 people). Sioux County has 16 active public water systems, and Rock Valley Water Supply is the 4th-largest of them by population served. Its population served is about 68% above the county average of 2,416 people per system, and accounts for 11% of the 38,650 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 Rock Valley Water Supply is about 39% 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 Rock Valley Water Supply?
EPA lists Rock Valley Water Supply as owned by a local government. 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. 13 of the 16 active systems in Sioux County (81%) are also owned by a local government.
Does Rock Valley Water Supply have drinking water violations?
Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in August 2024. The violations listed here began between October 1997 and August 2024. By type: 8 contaminant level above the legal limit and 4 monitoring and reporting. The contaminant or rule involved most often is Nitrate (8 of them). 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 |
|---|---|---|---|---|
| 2024-08-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2024-08-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2004-09-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2002-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 2000-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 2000-05-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 1999-12-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 1999-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 1999-05-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1998-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 1998-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Resolved |
| 1997-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | 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.
Rock Valley Water Supply: frequently asked questions
Who runs Rock Valley Water Supply?
Rock Valley Water Supply (PWSID IA8482096) is a community water system owned by a local government. It is regulated by the IA state drinking water program.
How many people does Rock Valley Water Supply serve?
Rock Valley Water Supply reports serving 4,059 people through 1,866 service connections in Sioux County, Iowa.
Where does Rock Valley Water Supply 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 Rock Valley Water Supply have any drinking water violations?
Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in August 2024. 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 Rock Valley Water Supply'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, 8 are health-based, and the most recent began in August 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the IA state drinking water program.
Where can I find Rock Valley Water Supply's water quality report?
As a community water system, Rock Valley Water Supply 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 Sioux County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Sioux Center Municipal Water Department | Sioux | 8,231 | Community | Groundwater |
| Orange City Municipal Water Department | Sioux | 6,267 | Community | Groundwater |
| Southern Sioux County Rural Water | Sioux | 5,420 | Community | Groundwater |
| Rural Water System #1 | Sioux | 3,428 | Community | Groundwater under influence of surface water |
| Hawarden Water Supply | Sioux | 2,700 | Community | Groundwater |
| Hull Water Supply | Sioux | 2,384 | 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, “Rock Valley Water Supply, PWSID IA8482096, Iowa”, https://aquacensus.com/water-systems/iowa/rock-valley-water-supply-ia8482096 (data as of October 1, 2026).