Public water system · SD4600233
ActiveOnida
At a glance
Onida (PWSID SD4600233) is an active community water system in Sully County, South Dakota. It reports serving 658 people through 410 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in August 2004.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
658
Service connections
410
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Onida compare with other water systems in Sully County?
By EPA's size categories, Onida is a small system (501 to 3,300 people). Sully County has 1 active public water system, and Onida is the largest of them by population served. Its population served is roughly in line with the county average of 658 people per system, and accounts for 100% of the 658 people reported by systems filed under the county. Across South Dakota, the 699 active systems average 1,387 people each. Nationally, the average active community water system reports serving 6,703 people, so Onida 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. South Dakota has 510 active community water systems, 73% of the state's 699 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 142 South Dakota systems (20%) list purchased surface water as their primary source.
Who owns and regulates Onida?
EPA lists Onida as owned by a local government. The SD state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 1 of the 1 active systems in Sully County (100%) are also owned by a local government.
Does Onida have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in August 2004. The violations listed here began between November 1997 and August 2004. By type: 8 public notice, recordkeeping or other and 4 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (5 of them). EPA lists 6 as resolved and 6 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 |
|---|---|---|---|---|
| 2004-08-02 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2003-07-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2002-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2001-03-10 | Public notice, recordkeeping or otherNotification, Public · code 06 | Lead and Copper Rulecode 5000 | No | Archived |
| 2000-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2000-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2000-02-13 | Public notice, recordkeeping or otherNotification, Public · code 06 | Lead and Copper Rulecode 5000 | No | Archived |
| 1999-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1998-08-09 | Public notice, recordkeeping or otherNotification, Public · code 06 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1998-06-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1997-11-09 | Public notice, recordkeeping or otherNotification, Public · code 06 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1997-11-08 | Public notice, recordkeeping or otherNotification, Public · code 06 | Total coliform bacteria (TCR)code 3100 | No | Archived |
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.
Onida: frequently asked questions
Who runs Onida?
Onida (PWSID SD4600233) is a community water system owned by a local government. It is regulated by the SD state drinking water program.
How many people does Onida serve?
Onida reports serving 658 people through 410 service connections in Sully County, South Dakota.
Where does Onida get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does Onida 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 August 2004. 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 Onida'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 August 2004. For current results, consult the system's annual water quality report, EPA ECHO, or the SD state drinking water program.
Where can I find Onida's water quality report?
As a community water system, Onida 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.
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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, “Onida, PWSID SD4600233, South Dakota”, https://aquacensus.com/water-systems/south-dakota/onida-sd4600233 (data as of October 1, 2026).