Water hardness in Chico
6.4 gpg moderately hard
Tap water in Chico is moderately hard: 6.4 gpg (110 mg/L · 6.2 °dH · 11 °fH).
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA0410002 (2026-06) · data checked 2026-10-19
Range across supply zones: 92–170 mg/L.
The figure is for California Water Service in Chico, from State Water Resources Control Board lab results. The median of 97 results from 2021 to 2026, taken at 55 well points, is 110 mg/L as CaCO3 (6.4 gpg), with a range of 91.6 to 170 mg/L. That is moderately hard water, and the top of the range reaches the hard band. Scale builds slowly.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 6.4 gpg |
|---|---|
| Utility | Cal-Water Service Co.-Chico |
How Chico compares
- Tap water in Chico is 29 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 954 of 1372 in the United States (1 = hardest); 29 % of these cities have softer water.
- In California it is number 239 of 336 cities; the regional median is 9.5 gpg.
- Nearest city with clearly softer water: Red Bluff, 59 km away (4.9 gpg).
- Nearest city with clearly harder water: Orland, 31 km away (11.8 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Chico
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 6 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H1 |
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 Chico water hard or soft?
It is moderately hard: 110 mg/L as CaCO₃ (6.4 gpg, 6.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Chico 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 Chico water?
6.4 gpg, equal to 6.2 °dH, 11 °fH or 110 mg/L calcium carbonate.
What dishwasher salt setting should I use in Chico?
For 110 mg/L (6.2 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Chico?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA0410002 (2026-06). Method: own measurement. California SWRCB Division of Drinking Water, EDT lab results, system CA0410002 · Outdated figure? Tell us