Public water system · SD4600002
ActiveCastlewood
At a glance
Castlewood (PWSID SD4600002) is an active community water system in Hamlin County, South Dakota. It reports serving 698 people through 328 service connections. Its primary water source is purchased groundwater, 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 June 2021.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
698
Service connections
328
Primary source
GWP
Purchased groundwater
System type
CWS
Community water system
System record
How does Castlewood compare with other water systems in Hamlin County?
By EPA's size categories, Castlewood is a small system (501 to 3,300 people). Hamlin County has 6 active public water systems, and Castlewood is the 3rd-largest of them by population served. Its population served is about 41% below the county average of 1,191 people per system, and accounts for 9.8% of the 7,145 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 Castlewood 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 groundwater means the system buys groundwater from another public water system rather than drawing its own. 100 South Dakota systems (14%) list purchased groundwater as their primary source.
Who owns and regulates Castlewood?
EPA lists Castlewood 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. 5 of the 6 active systems in Hamlin County (83%) are also owned by a local government.
Does Castlewood have drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in June 2021. The violations listed here began between July 1996 and June 2021. By type: 8 monitoring and reporting, 2 public notice, recordkeeping or other, 1 required treatment not met and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 11 as resolved and 1 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 |
|---|---|---|---|---|
| 2021-06-07 | Required treatment not metTreatment Technique No Certif. Operator · code 12 | Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400 | Yes | Resolved |
| 2002-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2002-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 1998-01-01 | Monitoring and reportingWater Quality Parameter M/R · code 53 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1997-01-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1996-07-13 | Public notice, recordkeeping or otherNotification, Public · code 06 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1996-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chlorobenzenecode 2989 | No | Resolved |
| 1996-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,2-Trichloroethanecode 2985 | No | Resolved |
| 1996-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Styrenecode 2996 | No | Resolved |
| 1996-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Resolved |
| 1996-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Resolved |
| 1996-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | 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.
Castlewood: frequently asked questions
Who runs Castlewood?
Castlewood (PWSID SD4600002) is a community water system owned by a local government. It is regulated by the SD state drinking water program.
How many people does Castlewood serve?
Castlewood reports serving 698 people through 328 service connections in Hamlin County, South Dakota.
Where does Castlewood get its water?
EPA SDWIS lists this system's primary water source as purchased groundwater. Purchased groundwater means the system buys groundwater from another public water system rather than drawing its own.
Does Castlewood 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 June 2021. 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 Castlewood'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 June 2021. For current results, consult the system's annual water quality report, EPA ECHO, or the SD state drinking water program.
Where can I find Castlewood's water quality report?
As a community water system, Castlewood 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 Hamlin County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Sioux Rural Water System | Hamlin + 3 more | 4,280 | Community | Groundwater |
| Estelline | Hamlin | 749 | Community | Purchased groundwater |
| Lake Norden | Hamlin | 554 | Community | Groundwater |
| Bryant | Hamlin | 471 | Community | Purchased groundwater |
| Hayti | Hamlin | 393 | 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, “Castlewood, PWSID SD4600002, South Dakota”, https://aquacensus.com/water-systems/south-dakota/castlewood-sd4600002 (data as of October 1, 2026).