Sioux City Water Hardness & Quality Report (2026)
Water Hardness
9.6 grains per gallon
Source
river
pH Level
7.9
neutral = 7.0
Lead
0.002 mg/L
✓ Below action level
TDS
275.6 mg/L
Est. Daily Cost
$0.44
energy & soap waste
Source: USGS Water Quality Portal · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Sioux City, your appliances are currently losing 22% efficiency due to mineral buildup.
| Appliance | In Sioux City | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 4.2 yrs | 8.5 yrs | -51% |
| Washing Machine | 7.5 yrs | 12 yrs | -38% |
| Water Heater | 9 yrs | 15 yrs | -40% |
Regional Water Comparison
How Sioux City compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Sioux City, Iowa | 164.5 mg/L | 3.5 ppt | 🟠 Hard | river |
| South Sioux City, Nebraska | 338 mg/L | 4.7 ppt | 🔴 Very Hard | groundwater |
| Yankton, South Dakota | 202 mg/L | 2.3 ppt | 🔴 Very Hard | groundwater |
| Fremont, Nebraska | 312.5 mg/L | 4.4 ppt | 🔴 Very Hard | groundwater |
| Sioux Falls, South Dakota | 373 mg/L | 3.6 ppt | 🔴 Very Hard | groundwater |
National Benchmark
How Sioux City compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Sioux City | 164.5 mg/L | 🟠 Moderate |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
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What Makes Sioux City's Water Unique?
Local geology and source profile
Sioux City, Iowa — a Missouri River city at the Iowa–Nebraska–South Dakota tripoint in Woodbury County — draws its municipal water supply from the Missouri River via the City of Sioux City Water Division, treating Missouri River water at the Floyd Boulevard Water Treatment Plant serving Sioux City and the metropolitan area. Sioux City is situated at the historic location where Lewis & Clark passed and where Sergeant Charles Floyd is buried. Water hardness in Sioux City measures 164.5 mg/L — classified as hard.
Sioux City's hard supply reflects the Missouri River's accumulated mineral load at the upper Missouri reach. The Missouri River near Sioux City drains the Northern Great Plains — the Cretaceous Pierre Shale (a massive calcareous marine shale formation extending from South Dakota through Nebraska — major calcium and sulfate contributor); the Cretaceous Niobrara Chalk (a highly calcareous chalk formation of western Nebraska and South Dakota); and the Quaternary loess plains of the Missouri Valley (calcareous wind-deposited material that leaches into Missouri tributaries). The Missouri River at the Sioux City reach, below the Gavins Point Dam (Lake Francis Case outflow), carries substantial mineral load from the Dakota, Niobrara, and Platte sub-basins.
At 164.5 mg/L, Sioux City residents face regular hard water challenges. Scale deposits form on faucet aerators, showerheads, and appliances within weeks — monthly descaling with citric acid solution is standard maintenance. Dishwashers require rinse-aid, and water heaters benefit from annual inspection. City of Sioux City Water Division consistently delivers water meeting all Iowa DNR and EPA Safe Drinking Water Act requirements.
Geology & Source: River supply from the Missouri River via the City of Sioux City Water Division — the Missouri River at the Sioux City reach collects calcareous Cretaceous Pierre Shale, Niobrara Chalk, and Quaternary loess drainage from the Great Plains; hard supply at 164.5 mg/L in Woodbury County at the Iowa–Nebraska–South Dakota tripoint.