Water hardness in Aomori
55 mg/L soft
Tap water in Aomori is soft: 55 mg/L (3.2 gpg · 3.1 °dH · 5.5 °fH).
Source: 青森市企業局水道部 Aomori City Waterworks Department, tap-water quality results FY2025 (2025) · data checked 2026-10-21
Range across supply zones: 12–128 mg/L.
Aomori uses the Yokouchi River at the Yokouchi plant and groundwater at some distribution sites. Hardness is reported at 55.2 mg/L CaCO₃, ranging from 11.6 to 128.0 mg/L (2025 data); the spread is wide, so the value at your tap depends on where in the supply area you live. Moderately soft water leaves visible deposits on kettles and taps over time, which regular descaling keeps in check.
Japanese waterworks report hardness (硬度) in mg/L CaCO₃; the standard is 300 mg/L and the target 10–100 mg/L.
Water data
| Total hardness | 55 mg/L |
|---|---|
| Utility | Aomori City Waterworks Department |
How Aomori compares
- Tap water in Aomori is 10 % harder than the median of the 228 cities we track in Japan (50 mg/L).
- By hardness it ranks 103 of 228 in Japan (1 = hardest); 55 % of these cities have softer water.
- Nearest city with clearly softer water: Hakodate, 107 km away (20 mg/L).
- Nearest city with clearly harder water: Hachinohe, 74 km away (132 mg/L).
Ranking of the hardest and softest water in Japan →
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 Aomori
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 3 °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 Aomori water hard or soft?
It is soft: 55 mg/L as CaCO₃ (3.2 gpg, 3.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Aomori safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Japanese waterworks report hardness (硬度) in mg/L CaCO₃; the standard is 300 mg/L and the target 10–100 mg/L.
How many grains per gallon is Aomori water?
3.2 gpg, equal to 3.1 °dH, 5.5 °fH or 55 mg/L calcium carbonate.
What dishwasher salt setting should I use in Aomori?
For 55 mg/L (3.1 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Aomori?
No. With soft water a softener adds nothing.
Source
Source: 青森市企業局水道部 Aomori City Waterworks Department, tap-water quality results FY2025 (2025). Method: figure published by the water supplier. 青森市企業局水道部 Aomori City Waterworks Department, tap-water quality results FY2025 · Outdated figure? Tell us