Sioux Falls – South Dakota – Water Quality Report 2025: PFAS Testing, Infrastructure Concerns & Safety across your city
Sioux Falls Water serves approximately 200,000 residents in South Dakota’s largest city, delivering an average of 38 million gallons of water daily during peak summer months and 17-18 million gallons per day in winter. The municipal utility operates an extensive distribution network spanning nearly every street in the city, supported by the Water Purification Plant with a treatment capacity of 75 million gallons per day following recent filter expansion completed in 2024.
Sioux Falls sources its drinking water from multiple sources including the Big Sioux Aquifer, Middle Skunk Creek Aquifer, limited use of the Big Sioux River, and the Lewis & Clark Regional Water System which draws from aquifers adjacent to the Missouri River. The water treatment process includes softening (reducing hardness by 50%), filtration, fluoridation, and chlorination to eliminate bacteria and viruses. Sioux Falls consistently meets all federal and state drinking water standards and has earned recognition as South Dakota’s best-tasting water multiple times, including first place in 2021 and third place nationally at the American Water Works Association competition in 2022.
Sioux Falls Water Quality: Current Status (2024-2025)
Latest Testing Results
- Comprehensive Testing Program: Sioux Falls performs over 170,000 water quality tests annually on more than 250 different substances, ensuring compliance with all federal and state drinking water safety standards.
- Real-Time Monitoring: Water quality parameters including chlorine, pH, and turbidity (cloudiness) are tested every two hours, with fluoride levels monitored daily and results posted to the city’s website.
- Federal Compliance: For the latest quarter assessed by the U.S. EPA (April 2024 – June 2024), Sioux Falls water was in full compliance with federal health-based drinking water standards.
Water Sources
- Big Sioux Aquifer: Primary groundwater source providing the majority of the city’s water supply from wells tapping the glacial outwash aquifer beneath the Big Sioux River flood plain.
- Middle Skunk Creek Aquifer: Secondary groundwater source providing additional supply security and system redundancy for continued service reliability.
- Lewis & Clark Regional Water System: Supplemental water purchased from this tri-state system that draws from aquifers adjacent to the Missouri River near Vermillion, providing Sioux Falls access to 28 million gallons per day capacity.
- Big Sioux River: Occasionally used as a supplemental source, though rarely utilized due to the reliability and quality of groundwater sources.
Advanced Treatment Technology
- Water Purification Plant: The main treatment facility utilizes a multi-barrier approach including 50% water softening, comprehensive filtration, fluoridation, and chlorination with a capacity of 75 million gallons per day.
- Filter Expansion Project: Recently completed in 2024, the plant expanded from 54 to 75 million gallons per day by adding five new filters, enhancing treatment capacity and efficiency to meet growing demand.
- Backwash Water Recycling: Advanced system recycles backwash water, reducing demand on the Big Sioux River and local aquifers while improving environmental sustainability.
Infrastructure Modernization
- Wellfield Development: Ongoing expansion of collector wells along the Big Sioux aquifer, including new high-capacity collector wells designed to provide additional capacity and system redundancy.
- Distribution Network: Comprehensive water main system spanning nearly every street in Sioux Falls, with continuous monitoring and maintenance to ensure reliable delivery throughout the growing metropolitan area.
- Master Planning: Long-term strategic planning addressing water system needs for the next 50-100 years, preparing for continued population growth and infrastructure requirements.
Quality Recognition and Customer Service
Sioux Falls Water has earned multiple awards for water quality and taste, winning first place as South Dakota’s best-tasting water in 2011, 2013, 2014, 2016, 2017, 2018, 2019, and 2021. In 2022, the city achieved third place nationally at the American Water Works Association competition, marking its first national recognition. The utility maintains transparent communication through regular water quality reports and daily monitoring results available on the city website. Customer service is available 24/7 at (605) 367-8131 for billing and service issues. The water division’s commitment to excellence ensures Sioux Falls residents receive not only safe, compliant drinking water but water that consistently ranks among the best-tasting in the region.
Recommendations for Sioux Falls Residents
Monitor Your Water
Stay informed about your water quality by checking the city’s daily water quality monitoring results posted at siouxfalls.gov/water-quality. Contact the Water Division at (605) 367-8131 for any water quality concerns or questions.
Follow Lawn Watering Rules
Adhere to Sioux Falls’ lawn watering program which has three conservation stages based on Big Sioux River levels, aquifer conditions, and daily water demand. Check current watering schedules and restrictions at siouxfalls.gov/water.
Consider Home Filtration
While Sioux Falls water meets all standards and wins taste competitions, homes may benefit from NSF-certified filters for personal preference or to address specific concerns like hardness, especially if you prefer softer water.
Practice Water Conservation
Help preserve water resources by following conservation practices, especially during peak summer months when demand reaches 38 million gallons daily. Simple measures like fixing leaks and efficient irrigation help maintain system reliability.
Report Issues Promptly
Contact Sioux Falls Utilities at (605) 367-8131 for any water service issues, billing questions, or to report water main breaks. The Water Division provides 24/7 customer service for urgent water system concerns.
Frequently Asked Questions
Is Sioux Falls tap water safe to drink?
Yes, Sioux Falls tap water is absolutely safe to drink and meets or exceeds all federal and state drinking water safety standards. The city performs over 170,000 water quality tests annually on more than 250 different substances to ensure safety and compliance.
Sioux Falls water sources include multiple aquifers and the Lewis & Clark Regional Water System, all of which undergo comprehensive treatment including softening, filtration, fluoridation, and chlorination. The city’s water has earned recognition as South Dakota’s best-tasting water multiple times and placed third nationally in 2022, demonstrating both safety and exceptional quality that exceeds basic compliance requirements.
Why is my water hard, and what can I do about it?
Sioux Falls water comes from groundwater aquifers that naturally contain dissolved minerals, making the water moderately hard. The water treatment process reduces hardness by 50%, but some mineral content remains.
Hard water can cause scale buildup on fixtures and appliances and may affect soap performance. While the city softens water during treatment, many residents choose to install home water softening systems for additional hardness reduction. Contact local water treatment professionals for home softening options, or call (605) 367-8131 for more information about the city’s water hardness levels and treatment process.
Where does Sioux Falls get its water?
Sioux Falls sources water from multiple reliable sources to ensure consistent supply:
• Big Sioux Aquifer: The primary source, drawing from groundwater wells that tap into the glacial aquifer beneath the Big Sioux River valley
• Middle Skunk Creek Aquifer: Secondary groundwater source providing additional system reliability
• Lewis & Clark Regional Water System: Supplemental water purchased from this tri-state system that draws from aquifers near the Missouri River, providing Sioux Falls access to 28 million gallons per day
• Big Sioux River: Occasionally used as a supplemental source, though rarely utilized due to excellent groundwater quality
This diversified approach ensures water security and system redundancy for the growing metropolitan area.
Are there current lawn watering restrictions?
Sioux Falls operates a lawn watering program with three conservation stages that adjust based on several factors:
Program Factors:
• Water availability in the Big Sioux River and Big Sioux Aquifer
• Daily water demand (peaks at 38 million gallons in summer vs. 17-18 million gallons in winter)
• Lewis & Clark Regional Water System availability
Current Status:
The specific stage and restrictions change seasonally and based on water system conditions. Check the current lawn watering schedule and any active restrictions by visiting siouxfalls.gov/water or calling (605) 367-8131. The city provides updated watering schedules and conservation guidelines to help residents use water efficiently while maintaining healthy lawns and gardens.
Contaminants of Concern
Arsenic
Source: Occurs naturally in soil and bedrock in parts of South Dakota and can also result from historical commercial activities like orchard spraying and coal ash disposal
Health Effects: Arsenic is a potent carcinogen that has been linked to skin, lung, bladder, kidney, and liver cancer with long-term exposure to elevated levels
Current Status: Third-party testing has found arsenic in Sioux Falls water, though the city maintains compliance with federal standards EPA Limit: 10 ppb maximum contaminant level
PFAS Compounds
Source: Per- and polyfluoroalkyl substances from firefighting foams used at Sioux Falls Regional Airport and Air National Guard base, as well as industrial processes and consumer products
Health Effects: Research suggests potential impacts on immune system, thyroid function, cholesterol levels, and possible links to certain cancers
Current Status: Sioux Falls suspended 21 wells suspected of PFAS contamination; all raw water samples are now tested for PFAS with no detections in current sources EPA Limits: New federal regulations for specific PFAS compounds were finalized in 2024
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