States → South Dakota
State profile · EPA SDWIS + UCMR5
South Dakota Drinking Water Quality
654 public water systems serve 915,901 people across South Dakota, with every Safe Drinking Water Act violation and UCMR5 PFAS result on record.
- 654
- Water systems
- 56,254
- Total violations
- 91.6%
- Systems w/ a violation
- 85.7%
- PFAS detection rate
The verdict
Across South Dakota, 599 of 654 water systems (91.6%) carry at least one EPA violation, and 42 of 49 UCMR5-tested systems show PFAS.
- 56,254
- Total EPA violations on record
- 15%
- Health-based (MCL / treatment)
- 91.6%
- Systems with ≥1 violation
- 85.7%
- UCMR5 PFAS detection rate
Water Systems
654
Total Violations
56,254
Violation Rate
91.6%
PFAS Detection
85.7%
42 of 49 tested
Violation Composition
How South Dakota's 56,254 violations break down by type, per EPA SDWIS classification.
Health-based (8,399) Monitoring/Reporting (47,855)
| Metric | Value | Share |
|---|---|---|
| Public water systems | 654 | - |
| Population served | 915,901 | - |
| Total violations | 56,254 | 100% |
| Health-based violations | 8,399 | 14.9% |
| Systems with violations | 599 | 91.6% |
| PFAS detection rate | 42 of 49 | 85.7% |
Health-based violations indicate the contaminant exceeded an EPA Maximum Contaminant Level (MCL) or treatment-technique requirement. Monitoring/reporting violations indicate procedural issues (missed tests, late reports) - not necessarily a contamination event.
Largest Water Systems
Sioux Falls
Sioux Falls, SD · 216,462 served
Rapid City
Rapid City, SD · 72,009 served
Aberdeen
Aberdeen, SD · 27,989 served
Brookings Municipal Utilities
Brookings, SD · 23,377 served
Watertown Municipal Utilities
Watertown, SD · 23,230 served
Web Water Development Association
Aberdeen, SD · 20,750 served
Mitchell
Mitchell, SD · 15,651 served
Yankton
Yankton, SD · 15,411 served
Huron
Huron, SD · 14,263 served
Pierre
Pierre, SD · 14,091 served
Box Elder
Box Elder, SD · 14,000 served
Minnehaha Community Water Corp
Dell Rapids, SD · 13,435 served
By Water District
Tabor, SD · 13,320 served
Spearfish
Spearfish, SD · 12,193 served
Mid-Dakota Rural Water
Miller, SD · 11,833 served
Vermillion
Vermillion, SD · 11,695 served
Rapid Valley Sanitary District
Rapid City, SD · 11,408 served
Brandon
Brandon, SD · 11,048 served
Harrisburg
Harrisburg, SD · 10,297 served
Ellsworth Afb
Ellsworth Afb, SD · 9,100 served
Most Violations
#1 Southbrook Estates Brookings
2,183 #2 Batesland Martin
827 #3 Huron Colony Huron
779 #4 Marvin South Shore
684 #5 Siphon Hill Water Association Rapid City
643 #6 Shirt Tail Gulch Development Black Hawk
622 #7 Rock Ridge Court Rapid City
607 #8 Provo Area Water System Edgemont
585 #9 Glendale Colony Frankfort
585 #10 Edelweiss Mountain Improvement Assoc Black Hawk
558 #11 Sacora Mobile Home Park Black Hawk
556 #12 Nisland Nisland
539 #13 76 Ranch Estates Black Hawk
531 #14 White Rock Colony Rosholt
523 #15 Buffalo Gap Buffalo Gap
514 Counties in South Dakota
Minnehaha
15 systems · 254,737 served
· 868 violations
Pennington
157 systems · 140,305 served
· 11,864 violations
Brookings
12 systems · 41,264 served
· 2,574 violations
Brown
21 systems · 38,081 served
· 1,750 violations
Lincoln
8 systems · 35,801 served
· 350 violations
Hughes
6 systems · 27,114 served
· 317 violations
Lawrence
73 systems · 25,648 served
· 6,945 violations
Codington
6 systems · 24,705 served
· 485 violations
Edmunds
8 systems · 23,620 served
· 157 violations
Meade
56 systems · 22,391 served
· 3,218 violations
Davison
4 systems · 19,917 served
· 178 violations
Bon Homme
7 systems · 18,388 served
· 575 violations
Clay
4 systems · 17,173 served
· 71 violations
Yankton
9 systems · 16,948 served
· 551 violations
Beadle
7 systems · 15,273 served
· 1,603 violations
Union
8 systems · 14,087 served
· 604 violations
Custer
51 systems · 13,071 served
· 2,359 violations
Charles Mix
6 systems · 10,052 served
· 378 violations
Lake
5 systems · 9,782 served
· 683 violations
Moody
7 systems · 9,401 served
· 920 violations
Butte
12 systems · 9,372 served
· 1,678 violations
Stanley
3 systems · 9,327 served
· 44 violations
Grant
5 systems · 9,119 served
· 827 violations
Tripp
3 systems · 8,104 served
· 262 violations
McCook
6 systems · 7,366 served
· 668 violations
Dewey
5 systems · 7,000 served
· 874 violations
Hamlin
6 systems · 6,877 served
· 434 violations
Fall River
14 systems · 6,440 served
· 1,994 violations
Roberts
11 systems · 6,241 served
· 1,527 violations
Kingsbury
7 systems · 5,786 served
· 523 violations
Showing top 30 of 65 counties.
Drinking Water Guides
Frequently Asked Questions
How many water systems are in South Dakota? ▼
South Dakota has 654 public water systems serving approximately 915,901 people. These include community water systems, non-transient non-community systems, and transient non-community systems regulated under the Safe Drinking Water Act.
How many drinking water violations are in South Dakota? ▼
South Dakota has 56,254 total drinking water violations on record, with 8,399 classified as health-based violations. 91.6% of water systems in the state have at least one violation.
Has PFAS been found in South Dakota drinking water? ▼
Of 49 water systems tested for PFAS in South Dakota, 42 had PFAS detected, a 85.7% detection rate. PFAS are persistent "forever chemicals" that do not break down in the environment.
What is the violation rate for South Dakota water systems? ▼
South Dakota's violation rate is 91.6%. This measures the percentage of public water systems that have at least one recorded violation in the EPA SDWIS database, including both health-based and monitoring/reporting violations.
Where does this South Dakota water data come from? ▼
All drinking water data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS is the federal database that tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources & Methodology
Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). PFAS testing data from the UCMR5 monitoring program. SDWIS tracks all public water systems regulated under the Safe Drinking Water Act.
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial
Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.