Water Hardness in Lake Oswego, OR
Oregon · 2 zip codes · 19 matched water systems
City avg (weighted): 12 PPM
Dataset updated March 9, 202619 matched water systems in the city rollupIndividual systems and ZIPs can differ. Methodology
Is Lake Oswego, OR Water Hard or Soft?
The displayed hardness for Lake Oswego, OR is 12 PPM (0.7 GPG) from Sunrise Water Authority, classified as soft. The citywide weighted average is 12 PPM.
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 19 matched water systems and 2 ZIP codes. 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 Lake Oswego
These systems are matched to Lake Oswego, OR. 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 |
|---|---|---|---|
| Sunrise Water Authority OR4100635 | surface water | 12 PPM SoftUSGS estimate: 51 PPM | |
| Lake Oswego Municipal Water OR4100457 | surface water | 12 PPM SoftUSGS estimate: 69 PPM | |
| Oregon City OR4101511 | surface water | 12 PPM SoftUSGS estimate: 18 PPM | |
| Oak Lodge Water Services OR4101512 | surface water | 12 PPM SoftUSGS estimate: 51 PPM | |
| Clackamas River Water OR4100187 | surface water | 12 PPM SoftUSGS estimate: 51 PPM |
Zip Codes in Lake Oswego, OR
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 Lake Oswego, OR.
Frequently Asked Questions
How hard is the water in Lake Oswego, OR?
The citywide weighted average water hardness in Lake Oswego, OR is 12 PPM (0.7 GPG), classified as soft. This is based on 19 matched water systems.
Do I need a water softener in Lake Oswego, OR?
At 12 PPM, the citywide average is relatively soft. A water softener is generally not necessary.
Is hard water in Lake Oswego, OR 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 Lake Oswego, OR?
Lake Oswego, Oregon is served by 19 matched water systems across 2 zip codes.
Learn More About Your Water
Water Hardness Scale: PPM and GPG Chart
Use the USGS water hardness scale to compare PPM, GPG, and mg/L levels from soft to very hard water.
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Compare free lookups, soap tests, test strips, liquid drop kits, and lab tests for measuring water hardness.
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