TapWaterGuide
Worldwide water safety reference
United States Last reviewed:

South Dakota Tap Water Quality

about 470
Community water systems
City reports on this site
3
Tracked contaminants
August 28, 2026
Data reviewed

Check a South Dakota ZIP Code

Overview

Sioux Falls blends Big Sioux aquifer wells with Missouri River water from the Lewis & Clark regional pipeline, a multi-state project that has transformed supply reliability across the region; Rapid City draws clean Black Hills sources. Both comply fully.

Rural South Dakota mirrors its neighbors: naturally mineral-heavy prairie groundwater (iron, sulfates, TDS) pushed the state into regional rural water systems, agricultural nitrate pressures shallow wells, and scattered arsenic and uranium occurrences track Black Hills geology and legacy mining at Edgemont.

Common Contaminants in South Dakota

Nitrate

Shallow ag-area wells and a few small systems exceed limits after wet cycles

Sulfates, iron, TDS

Natural prairie groundwater character: the driver for regional pipeline supply rather than a health violation

Arsenic and uranium

Localized Black Hills-area occurrences in wells; testing recommended

Violations & Compliance

Compliance is solid, strengthened as Lewis & Clark pipeline water replaces marginal local wells; remaining violations are small-system nitrate and monitoring lapses.

City Reports for South Dakota

We haven't published individual city water reports for South Dakota yet. Use the ZIP lookup for a statewide assessment, and check your utility's annual Consumer Confidence Report for local detail.

Frequently Asked Questions

Sources & References

The safety rating and guidance on this page draw on the following sources. See our full methodology.