Ottawa Water Hardness & Quality Report (2026)
Water Hardness
7.8 grains per gallon
Source
river
pH Level
7.8
neutral = 7.0
Lead
0.002 mg/L
✓ Below action level
TDS
230.7 mg/L
Est. Daily Cost
$0.36
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 Ottawa, your appliances are currently losing 18% efficiency due to mineral buildup.
| Appliance | In Ottawa | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 5.2 yrs | 8.5 yrs | -39% |
| Washing Machine | 8.6 yrs | 12 yrs | -28% |
| Water Heater | 10.2 yrs | 15 yrs | -32% |
Regional Water Comparison
How Ottawa compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Ottawa, Illinois | 134 mg/L | 4.8 ppt | 🟠 Hard | river |
| Streator, Illinois | 130.5 mg/L | 4.7 ppt | 🟠 Hard | river |
| Morris, Illinois | 154 mg/L | 5.5 ppt | 🟠 Hard | river |
| Yorkville, Illinois | 275 mg/L | 9.6 ppt | 🔴 Very Hard | river |
| DeKalb, Illinois | 136 mg/L | 4.9 ppt | 🟠 Hard | river |
National Benchmark
How Ottawa compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Ottawa | 134 mg/L | 🟠 Moderate |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
Bring Badger-quality water to your Ottawa home
Shop water softeners on Amazon.com →
What Makes Ottawa's Water Unique?
Local geology and source profile
Ottawa, Illinois, in LaSalle County — the LaSalle County seat adjacent to Streator and Marseilles, where the Illinois River and Fox River meet at the Illinois River valley in the Illinois and Michigan Canal corridor — receives its municipal water from the City of Ottawa Water Division, drawing from the Illinois River at the Ottawa water treatment plant.
The moderately hard 134 mg/L hardness and TDS of 230.7 mg/L reflect the Illinois River's Fox Valley-Silurian dolomite carbonate character at Ottawa. The Illinois River at Ottawa receives Fox River inflow (draining the Silurian Niagara Dolomite Fox Valley — very hard), diluted by the broader Illinois River drainage. The primary hardness contributors are the Silurian Niagara Dolomite (carbonate platform beneath Kane-Kendall-LaSalle Counties) and calcareous Pleistocene Wisconsin till.
At 134 mg/L, Ottawa's water is moderately hard — scale builds in kettles and appliances over months, dishwashers benefit from rinse aid, and faucet aerators need periodic cleaning. Quarterly descaling is appropriate. The PFAS level of 4.8 ppt warrants a certified drinking water filter — the Illinois River PFAS legacy (north Illinois industrial corridor), the LaSalle County manufacturing history, and the central Illinois PFAS background contribute to Ottawa's readings.
Geology & Source: Ottawa in LaSalle County draws from the Ottawa Water Division on the Illinois River (LaSalle County, Illinois Valley) — the Illinois River drains the Silurian Niagara Dolomite (Kane-LaSalle Counties) and calcareous Pleistocene till — Illinois Valley Silurian dolomite and till carbonate drainage produces moderately hard water at 134 mg/L with TDS 231 mg/L in this LaSalle County Illinois city.