Water hardness in Portland
2.6 gpg soft
Tap water in Portland is soft: 2.6 gpg (45 mg/L · 2.5 °dH · 4.5 °fH).
Source: Portland Water Bureau 2025 Water Quality Report (print version) (2025) · data checked 2026-10-19
Range across supply zones: 7–80 mg/L.
2 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| gpg | mg/L | ||
|---|---|---|---|
| Bull Run watershed (surface water; main supply) | 0.5 | 9 | soft |
| Columbia South Shore Well Field (groundwater) | 4.7 | 80 | moderately hard |
Portland's main supply is the Bull Run watershed, which the Water Bureau says typically has a total hardness of 7 to 11 mg/L (0.5 gpg). The 9 mg/L on this page is the midpoint of that range, so it is computed, not a measured average. A groundwater supply also exists, and some areas can receive harder well water at times. Scale is minor with Bull Run water.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 2.6 gpg |
|---|---|
| Utility | Portland Water Bureau |
How Portland compares
- Tap water in Portland is 71 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 1237 of 1372 in the United States (1 = hardest); 10 % of these cities have softer water.
- In Oregon it is number 5 of 13 cities; the regional median is 2.1 gpg.
- Nearest city with clearly softer water: Tigard, 12 km away (1.9 gpg).
- Nearest city with clearly harder water: Vancouver, 14 km away (6.4 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 Portland
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 2 °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 Portland water hard or soft?
It is soft: 45 mg/L as CaCO₃ (2.6 gpg, 2.5 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Portland 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 Portland water?
2.6 gpg, equal to 2.5 °dH, 4.5 °fH or 45 mg/L calcium carbonate.
What dishwasher salt setting should I use in Portland?
For 45 mg/L (2.5 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Portland?
No. With soft water a softener adds nothing.
Source
Source: Portland Water Bureau 2025 Water Quality Report (print version) (2025). Method: figure published by the water supplier. Portland Water Bureau 2025 Water Quality Report (print version) · Outdated figure? Tell us