Public water system · SD4600224
ActiveNew Underwood
At a glance
New Underwood (PWSID SD4600224) is an active community water system in Pennington County, South Dakota. It reports serving 679 people through 269 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, 9 are health-based, and the most recent began in October 2022.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
679
Service connections
269
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does New Underwood compare with other water systems in Pennington County?
By EPA's size categories, New Underwood is a small system (501 to 3,300 people). Pennington County has 150 active public water systems. Its population served is about 27% below the county average of 930 people per system, and accounts for 0.5% of the 139,467 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 New Underwood 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. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 431 South Dakota systems (62%) list groundwater as their primary source.
Who owns and regulates New Underwood?
EPA lists New Underwood 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. 12 of the 150 active systems in Pennington County (8%) are also owned by a local government.
Does New Underwood have drinking water violations?
Of the 12 most recent violations in EPA's records, 9 are health-based, and the most recent began in October 2022. The violations listed here began between April 2009 and October 2022. By type: 9 contaminant level above the legal limit, 1 monitoring and reporting, 1 monitoring and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Gross alpha (excluding radon and uranium) (5 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 |
|---|---|---|---|---|
| 2022-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2022-10-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2013-05-26 | Public notice, recordkeeping or otherSanitary Survey (TCR) · code 28 | Not reported | No | Resolved |
| 2010-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Gross alpha (excluding radon and uranium)code 4000 | Yes | Resolved |
| 2010-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2010-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Gross alpha (excluding radon and uranium)code 4000 | Yes | Resolved |
| 2010-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2009-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2009-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Gross alpha (excluding radon and uranium)code 4000 | Yes | Resolved |
| 2009-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Gross alpha (excluding radon and uranium)code 4000 | Yes | Resolved |
| 2009-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2009-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Gross alpha (excluding radon and uranium)code 4000 | 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.
New Underwood: frequently asked questions
Who runs New Underwood?
New Underwood (PWSID SD4600224) is a community water system owned by a local government. It is regulated by the SD state drinking water program.
How many people does New Underwood serve?
New Underwood reports serving 679 people through 269 service connections in Pennington County, South Dakota.
Where does New Underwood 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 New Underwood have any drinking water violations?
Of the 12 most recent violations in EPA's records, 9 are health-based, and the most recent began in October 2022. 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 New Underwood'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, 9 are health-based, and the most recent began in October 2022. For current results, consult the system's annual water quality report, EPA ECHO, or the SD state drinking water program.
Where can I find New Underwood's water quality report?
As a community water system, New Underwood 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 Pennington County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Rapid City | Pennington | 72,009 | Community | Surface water |
| Box Elder | Pennington | 14,000 | Community | Groundwater |
| Rapid Valley Sanitary District | Pennington | 11,408 | Community | Surface water |
| Ellsworth Afb | Pennington | 9,100 | Community | Purchased surface water |
| Nps-Mount Rushmore National Memorial | Pennington | 4,100 | Non-transient non-community | Groundwater |
| Colonial Pine Hills Sanitary Distric | Pennington | 1,200 | 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, “New Underwood, PWSID SD4600224, South Dakota”, https://aquacensus.com/water-systems/south-dakota/new-underwood-sd4600224 (data as of October 1, 2026).