Water hardness in Lake Oswego
1.5 gpg soft
Tap water in Lake Oswego is soft: 1.5 gpg (25 mg/L · 1.4 °dH · 2.5 °fH).
Source: City of Lake Oswego Water Quality Report 2017 (2017) · data checked 2026-11-02
This figure is over 3 years old; hardness may have changed.
Lake Oswego runs its own municipal water system. The newest figure we hold is from the city's 2017 report: 25 mg/L as CaCO3, which is soft. The data is several years old, so treat it as indicative. Scale is unlikely to be an issue at this level.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 1.5 gpg |
|---|---|
| Utility | City of Lake Oswego Water |
How Lake Oswego compares
- Tap water in Lake Oswego is 84 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 1302 of 1372 in the United States (1 = hardest); 5 % of these cities have softer water.
- In Oregon it is number 11 of 13 cities; the regional median is 2.1 gpg.
Ranking of the hardest and softest water in the United States →
What it means at home
- Little or no limescale in kettles, water heaters or washing machines.
- Soap lathers easily; water does not dry skin or hair.
- Dishwasher: salt setting at minimum or off.
- No softener needed; a jug filter only changes taste.
How much salt will you use for softening?
No. Water this soft does not need softening.
Descale a coffee machine or kettle about every 6 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Lake Oswego
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 1 °dH |
| AEG / Electrolux | 1 |
| Beko | 1st |
| Hoover | S0 |
| LG | H0 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Lake Oswego water hard or soft?
It is soft: 25 mg/L as CaCO₃ (1.5 gpg, 1.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Lake Oswego safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
How many grains per gallon is Lake Oswego water?
1.5 gpg, equal to 1.4 °dH, 2.5 °fH or 25 mg/L calcium carbonate.
What dishwasher salt setting should I use in Lake Oswego?
For 25 mg/L (1.4 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Lake Oswego?
No. With soft water a softener adds nothing.
Source
Source: City of Lake Oswego Water Quality Report 2017 (2017). Method: figure published by the water supplier. City of Lake Oswego Water Quality Report 2017 · Outdated figure? Tell us