Water Hardness in Ottawa, IL
Illinois · 1 zip codes · 7 matched water systems
Dataset updated March 9, 20267 matched water systems in the city rollupIndividual systems and ZIPs can differ. Methodology
Is Ottawa, IL Water Hard or Soft?
The citywide weighted average water hardness in Ottawa, IL is 147 PPM (8.6 GPG), classified as moderately hard. Individual systems, ZIP codes, and private wells can differ.
Water hardness is not a drinking-water safety score. It measures calcium and magnesium minerals, and address-level results can shift by pressure zone, supply blend, building plumbing, or private well.
How this city reading is built
This city reading is a weighted rollup across 7 matched water systems and 1 ZIP code. Citywide readings are useful for comparison, but individual utility zones and ZIPs can differ.
Hardness is a mineral-content reading, not a drinking-water safety rating. Use it for scale, appliance, and softener decisions; check your utility report or test your tap before sizing treatment equipment. See how we calculate local readings.
Water Systems in Ottawa
These systems are matched to Ottawa, IL. Citywide readings are useful for comparison, but the system serving a specific address may differ from the city average.
| Water System | Source | Hardness | Pop. Served |
|---|---|---|---|
| Ottawa IL0990800 | groundwater | 147 PPM Moderately Hard | |
| Naplate IL0990600 | groundwater | 147 PPM Moderately Hard | |
| Fields Hill Improvement Association IL0995150 | groundwater | 147 PPM Moderately Hard | |
| Retz Addn Improvement Association IL0995400 | groundwater | 147 PPM Moderately Hard | |
| La Salle County Nursing Home IL0995329 | groundwater | 147 PPM Moderately Hard |
Zip Codes in Ottawa, IL
What This Means For You
Use this city reading as a local planning estimate, not a final treatment specification. Hardness can vary by utility zone, seasonal blend, private well, and building plumbing. Confirm your tap reading with a utility report or home hardness test before sizing equipment.
Know your water hardness?
If you've tested your water or have your utility's CCR report, share your reading to help us improve accuracy for Ottawa, IL.
Frequently Asked Questions
How hard is the water in Ottawa, IL?
The citywide weighted average water hardness in Ottawa, IL is 147 PPM (8.6 GPG), classified as moderately hard. This is based on 7 matched water systems.
Do I need a water softener in Ottawa, IL?
With a citywide average hardness of 147 PPM, a water softener is worth considering for homes in Ottawa. Confirm your tap reading before sizing equipment.
Is hard water in Ottawa, IL safe to drink?
Water hardness itself is a mineral-content reading, not a drinking-water safety rating. Calcium and magnesium are naturally occurring minerals, but you should check your utility's Consumer Confidence Report for contaminant and compliance information.
How many water systems serve Ottawa, IL?
Ottawa, Illinois is served by 7 matched water systems across 1 zip code.
Learn More About Your Water
How to Test Water Hardness at Home
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