Public water system · SD4600175
ActiveIsabel
At a glance
Isabel (PWSID SD4600175) is an active community water system in Dewey County, South Dakota. It reports serving 145 people through 135 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, 2 are health-based, and the most recent began in November 2015.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
145
Service connections
135
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Isabel compare with other water systems in Dewey County?
By EPA's size categories, Isabel is a very small system (500 people or fewer). Dewey County has 5 active public water systems, and Isabel is the 5th-largest of them by population served. Its population served is well below the county average of 1,400 people per system, and accounts for 2.1% of the 7,000 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 Isabel 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 Isabel?
EPA lists Isabel 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. 3 of the 5 active systems in Dewey County (60%) are also owned by a local government.
Does Isabel have drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in November 2015. The violations listed here began between March 2004 and November 2015. By type: 5 monitoring and reporting, 5 public notice, recordkeeping or other and 2 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (6 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 |
|---|---|---|---|---|
| 2015-11-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2010-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2010-01-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2008-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2007-08-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2006-04-10 | Public notice, recordkeeping or otherPublic Notification Violation without NPDWR Violation · code 76 | Public Noticecode 7500 | No | Resolved |
| 2006-01-10 | Public notice, recordkeeping or otherPublic Notification Violation without NPDWR Violation · code 76 | Public Noticecode 7500 | No | Resolved |
| 2005-10-10 | Public notice, recordkeeping or otherPublic Notification Violation without NPDWR Violation · code 76 | Public Noticecode 7500 | No | Resolved |
| 2005-07-10 | Public notice, recordkeeping or otherPublic Notification Violation without NPDWR Violation · code 76 | Public Noticecode 7500 | No | Resolved |
| 2004-05-02 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2004-03-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2004-03-01 | 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.
Isabel: frequently asked questions
Who runs Isabel?
Isabel (PWSID SD4600175) is a community water system owned by a local government. It is regulated by the SD state drinking water program.
How many people does Isabel serve?
Isabel reports serving 145 people through 135 service connections in Dewey County, South Dakota.
Where does Isabel 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 Isabel have any drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in November 2015. 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 Isabel'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, 2 are health-based, and the most recent began in November 2015. For current results, consult the system's annual water quality report, EPA ECHO, or the SD state drinking water program.
Where can I find Isabel's water quality report?
As a community water system, Isabel 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 Dewey County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Eagle Butte | Dewey | 4,000 | Community | Purchased surface water |
| Tri-County Rural Water System | Dewey + 2 more | 2,190 | Community | Surface water |
| Timber Lake | Dewey | 499 | Community | Groundwater |
| T C & G Rural Water System | Dewey | 166 | Community | 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, “Isabel, PWSID SD4600175, South Dakota”, https://aquacensus.com/water-systems/south-dakota/isabel-sd4600175 (data as of October 1, 2026).