National Drinking Water Database
South Dakota
250 systems serving 785,973 people
This drinking water quality report shows results of tests conducted by water utilities in South Dakota, provided to the Environmental Working Group (EWG) by the South Dakota Department of Environment & Natural Resources. It is part of EWG's national database that includes 47,667 drinking water utilities and 20 million test results from 45 states and the District of Columbia. Water utilities nationwide detected more than 300 pollutants between 2004 and 2009. More than half of these chemicals are unregulated, legal in any amount. Despite this widespread contamination, the federal government invests few resources in protecting rivers, reservoirs, and groundwater from pollution in the first place. The information below summarizes drinking water quality for this state.
Chemicals |
Water Utilities |
Population Served |
|
|---|---|---|---|
| Detected Chemicals | 26 |
250 |
658,214 |
Exceed health guidelines* | 15 |
165 |
514,247 |
Exceed Legal Limits* | 9 |
20 |
13,805 |
Unregulated chemicals detected | 1 |
1 |
297 |
| * Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance. | |||
15 Contaminants Exceeding Health Based Limits
Contaminants detected in South Dakota drinking water above health guidelines, according to an Environmental Working Group analysis of data obtained from state water authorities
| Contaminant | Population |
Number of Systems |
||
|---|---|---|---|---|
| At Any Level | Above Health Limits | At Any Level | Above Health Limits | |
| Arsenic (total) | 398,179 | 398,179 | 78 | 78 |
| Alpha particle activity (excl radon and uranium) | 216,113 | 216,113 | 97 | 97 |
| Radium-226 | 109,997 | 109,997 | 36 | 36 |
| Radium-228 | 104,998 | 104,998 | 37 | 37 |
| Total trihalomethanes (TTHMs) | 33,068 | 32,463 | 10 | 9 |
| Total haloacetic acids (HAAs) | 32,463 | 32,463 | 9 | 9 |
| Trichloroethylene | 13,876 | 13,876 | 1 | 1 |
| Mercury (total inorganic) | 3,798 | 876 | 7 | 1 |
| 1,2-Dichloroethane | 775 | 775 | 1 | 1 |
| Nitrate | 454,213 | 387 | 176 | 2 |
Water Utilities in South Dakota Reporting Chemicals Exceeding Health Guidelines
Water utilities in South Dakota reporting chemicals exceeding health guidelines, according to an Environmental Working Group analysis of data obtained from state water authorities, include:
| System | Population |
Chemicals tested |
Chemicals found |
Chemicals exceeding health guidelines |
|---|---|---|---|---|
| Castlewood | 666 | 84 | 11 | 5 |
| Shirt Tail Gulch Development | 55 | 82 | 7 | 4 |
| Rapid City | 67,430 | 82 | 7 | 4 |
| Saint Onge Sewer & Water Co | 255 | 82 | 6 | 4 |
| Hot Springs | 5,055 | 74 | 5 | 4 |
| Edgemont | 867 | 74 | 6 | 4 |
| Buffalo Gap | 164 | 73 | 5 | 4 |
| Bonesteel | 297 | 17 | 8 | 4 |
| Heartland Country Ranchettes | 92 | 82 | 6 | 3 |
| Cottonwood Grove Mobile Home Park | 29 | 82 | 6 | 3 |
| Rainbow Water Company | 162 | 82 | 5 | 3 |
| Jamesville Colony | 120 | 82 | 6 | 3 |
| Keystone | 370 | 82 | 5 | 3 |
| Country Village/North | 292 | 74 | 4 | 3 |
| Country Club Estates | 52 | 74 | 4 | 3 |
| Ponderosa Park | 40 | 73 | 3 | 3 |
| Blucksberg Mtn Water Association | 528 | 40 | 6 | 3 |
| Rapid Valley Sanitary District | 7,713 | 82 | 7 | 3 |
| Edelweiss Mountain Improvement Assoc | 63 | 82 | 5 | 3 |
| Colonial Pine Hills | 1,260 | 82 | 5 | 3 |
Sources of South Dakota Drinking Water Contaminants
The contaminants identified in South Dakota drinking water come from a wide variety of sources, including agriculture, industry, water treatment plants, and polluted storm runoff from urban areas.
Testing Summary for South Dakota
The federal government has set standards for some of the pollutants found in tap water supplies.
| Contaminants reported as tested by water suppliers in South Dakota | 85 | |
| Contaminants tested due to federal law: | 73 | |
| Contaminants tested in addition to those required by federal law: | 12 | |
Violation Summary for South Dakota
Data from the U.S. Environmental Protection Agency includes the following violations of federal standards in South Dakota since 2004
| Violation Type | Number of Violations |
|---|---|
| Failure to monitor regularly | 1,715 |
| Over maximum contaminant level, Average | 248 |
| Public Notification Violation for National Primary Drinking Water Regulations | 201 |
| Monitoring and Reporting Disinfection Byproduct Rule | 183 |
| Failure to report information to the public or state agency in the Consumer Confidence Report | 126 |
| Failure to monitor, Routine Major (Coliform bacteria) | 116 |
| Maximum contaminant level, Monthly (Coliform bacteria) | 102 |
| Treatment Technique No Certif. Operator | 62 |
| Failure to monitor, Routine Minor (Coliform bacteria) | 38 |
| Failure to monitor, Repeat Major (Coliform bacteria) | 34 |
| Follow-up and Routine Tap Sampling | 24 |
| Other Non-National Primary Drinking Water Regulations Potential Health Risks | 17 |
| Inadequate reporting of information to the public | 16 |
| Failure to monitor, Repeat Minor (Coliform bacteria) | 10 |
| Initial Tap Sampling for Lead and Copper | 7 |
| Maximum contaminant level, Acute (Coliform bacteria) | 6 |
| Excess Turbidity at 0.3 NTU | 5 |
| Public Education | 4 |
| Over maximum contaminant level, Single Sample | 3 |
| Improper Treatment Techniques | 2 |
| Excess Turbidity at 1 NTU | 1 |
| Treatment Technique Precursor Removal | 1 |
| Filter Turbidity Reporting | 1 |