Water hardness in Davis
26.3 gpg very hard
Tap water in Davis is very hard: 26.3 gpg (450 mg/L · 25.2 °dH · 45 °fH).
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA5710001 (2025-08) · data checked 2026-10-19
Range across supply zones: 106–624 mg/L.
The Davis figure comes from State Water Resources Control Board lab results for the City of Davis system. The median of 27 results from 2021 to 2025, taken at 6 well points, is 450 mg/L as CaCO3 (26.3 gpg), with a range of 106 to 624 mg/L. This is among the hardest water in our US set. Scale builds very fast, and a softener is worth serious consideration.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 26.3 gpg |
|---|---|
| Utility | City Of Davis |
How Davis compares
- Tap water in Davis is 190 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 26 of 1372 in the United States (1 = hardest); 98 % of these cities have softer water.
- In California it is number 11 of 336 cities; the regional median is 9.5 gpg.
- Nearest city with clearly softer water: Woodland, 13 km away (5 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Davis
| Brand | Setting for this water |
|---|---|
| Bosch | H06 |
| Miele | 25 °dH |
| AEG / Electrolux | 6 |
| Beko | 6th |
| Hoover | S3 |
| LG | H4 |
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 Davis water hard or soft?
It is very hard: 450 mg/L as CaCO₃ (26.3 gpg, 25.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Davis 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 Davis water?
26.3 gpg, equal to 25.2 °dH, 45 °fH or 450 mg/L calcium carbonate.
What dishwasher salt setting should I use in Davis?
For 450 mg/L (25.2 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Davis?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA5710001 (2025-08). Method: own measurement. California SWRCB Division of Drinking Water, EDT lab results, system CA5710001 · Outdated figure? Tell us