Comprehensive Water Quality Monitoring

The City of Sioux Falls receives its drinking water from the Big Sioux River (surface water), the Big Sioux Aquifer, the Middle Skunk Creek Aquifer (ground water), and treated water from the Lewis and Clark Regional Water System. All drinking water sources (both tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and wells. All of these sources contain some naturally occurring substances. As water travels over the surface of the land or through the ground, it dissolves naturally occurring minerals and, in some cases, radioactive material. It can also pick up substances resulting from the presence of people and animals. Water from the river, wells, treatment plant, and taps throughout Sioux Falls is tested regularly to screen for these substances so steps can be taken before harmful levels occur. Samples are tested at the water plant lab, the city and state health lab, and several contract labs specializing in drinking water analysis. Substances that may be present are divided into five basic testing groups and include:

• Microbial contaminants (such as viruses and bacteria) may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
• Inorganic contaminants (such as salts and metals) may occur naturally or result from urban storm water runoff, sewage treatment plant discharges, oil and gas production, mining, or farming.
• Pesticides and herbicides may come from urban storm water runoff, residential uses, and agriculture.
• Organic chemical contaminants (including synthetic and volatile organic chemicals) may be by-products of industrial and petroleum production, urban storm water runoff, gas stations, and septic systems.
• Radioactive contaminants may be naturally occurring or the result of oil and gas production and mining activities.

The City of Sioux Falls tests for more than 100 regulated and many other nonregulated contaminants in the drinking water. Only those regulated contaminants that are detected are listed on this report.

Additional water quality data from the City of Sioux Falls and the Lewis and Clark system may be found on the City’s website at siouxfalls.gov/water.

No health-based drinking water quality violations were recorded in 2023.