Water hardness in Kennewick
7.3 gpg hard
Tap water in Kennewick is hard: 7.3 gpg (125 mg/L · 7 °dH · 12.5 °fH).
Source: City of Kennewick Annual Water Quality Report (2025 data) (2025) · data checked 2026-10-20
Range across supply zones: 50–200 mg/L.
The City of Kennewick's 2025 water report publishes only a range for hardness, 50 to 200 mg/L (about 3 to 12 gpg), and no average. The 125 mg/L (7.3 gpg) on this page is the midpoint of that range, so it is computed, not a measured mean. At the midpoint the water is hard, but the range runs from soft to very hard. Treat the figure as a rough guide.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 7.3 gpg |
|---|---|
| Utility | City of Kennewick Water Utility |
How Kennewick compares
- Tap water in Kennewick is 19 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 863 of 1372 in the United States (1 = hardest); 37 % of these cities have softer water.
- In Washington it is number 3 of 27 cities; the regional median is 2.8 gpg.
- Nearest city with clearly softer water: Yakima, 114 km away (1.6 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 Kennewick
| Brand | Setting for this water |
|---|---|
| Bosch | H01 |
| Miele | 7 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| 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 Kennewick water hard or soft?
It is hard: 125 mg/L as CaCO₃ (7.3 gpg, 7 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Kennewick 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 Kennewick water?
7.3 gpg, equal to 7 °dH, 12.5 °fH or 125 mg/L calcium carbonate.
What dishwasher salt setting should I use in Kennewick?
For 125 mg/L (7 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Kennewick?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: City of Kennewick Annual Water Quality Report (2025 data) (2025). Method: computed from supplier's calcium and magnesium. City of Kennewick Annual Water Quality Report (2025 data) · Outdated figure? Tell us