Water hardness in Spokane
9.3 gpg hard
Tap water in Spokane is hard: 9.3 gpg (159 mg/L · 8.9 °dH · 15.9 °fH).
Source: City of Spokane 2025 Technical Drinking Water Report (2025) · data checked 2026-10-19
Range across supply zones: 91–360 mg/L.
The City of Spokane's 2025 technical report lists hardness as CaCO3 for eight source wells. The mean is 159 mg/L (9.3 gpg), with wells from 90.6 to 360 mg/L. The 360 mg/L value is a single well. The water is hard, and what reaches your tap depends on which wells feed your area.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 9.3 gpg |
|---|---|
| Utility | City of Spokane Water Department |
How Spokane compares
- Tap water in Spokane is close to the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 678 of 1372 in the United States (1 = hardest); 51 % of these cities have softer water.
- In Washington it is number 1 of 27 cities; the regional median is 2.8 gpg.
- Nearest city with clearly softer water: Lewiston, 145 km away (2.1 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Fast scale on taps, shower screens and kettle; white spots on glassware.
- Water heater: efficiency loss and element failures within years if unprotected.
- Dry skin and dull hair after showering are common.
- Softener recommended; jug or reverse osmosis for drinking.
How much salt will you use for softening?
Recommended, especially with a heater or boiler: scale cuts efficiency and shortens its life.
Descale a coffee machine or kettle about every 2 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Spokane
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 9 °dH |
| AEG / Electrolux | 2 |
| Beko | 3rd |
| Hoover | S1 |
| LG | H2 |
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 Spokane water hard or soft?
It is hard: 159 mg/L as CaCO₃ (9.3 gpg, 8.9 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Spokane 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 Spokane water?
9.3 gpg, equal to 8.9 °dH, 15.9 °fH or 159 mg/L calcium carbonate.
What dishwasher salt setting should I use in Spokane?
For 159 mg/L (8.9 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Spokane?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: City of Spokane 2025 Technical Drinking Water Report (2025). Method: figure published by the water supplier. City of Spokane 2025 Technical Drinking Water Report · Outdated figure? Tell us