Water hardness in Santa Maria
26.9 gpg very hard
Tap water in Santa Maria is very hard: 26.9 gpg (460 mg/L · 25.8 °dH · 46 °fH).
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA4210011 (2026-06) · data checked 2026-10-19
Range across supply zones: 400–610 mg/L.
The Santa Maria figure comes from State Water Resources Control Board lab results for the City of Santa Maria Utilities Department. The median of 51 results from 2021 to 2026 is 460 mg/L as CaCO3 (26.9 gpg), with a range of 400 to 610 mg/L. The sampling points are treatment plants and wells. This is among the hardest water in our US set, 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 | 26.9 gpg |
|---|---|
| Utility | City Of Santa Maria Utilities Department |
How Santa Maria compares
- Tap water in Santa Maria is 197 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 22 of 1372 in the United States (1 = hardest); 98 % of these cities have softer water.
- In California it is number 9 of 336 cities; the regional median is 9.5 gpg.
- Nearest city with clearly softer water: Arroyo Grande, 25 km away (20.4 gpg).
- Nearest city with clearly harder water: Solvang, 47 km away (34.6 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 Santa Maria
| Brand | Setting for this water |
|---|---|
| Bosch | H06 |
| Miele | 26 °dH |
| AEG / Electrolux | 6 |
| Beko | 6th |
| Hoover | S4 |
| 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 Santa Maria water hard or soft?
It is very hard: 460 mg/L as CaCO₃ (26.9 gpg, 25.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Santa Maria 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 Santa Maria water?
26.9 gpg, equal to 25.8 °dH, 46 °fH or 460 mg/L calcium carbonate.
What dishwasher salt setting should I use in Santa Maria?
For 460 mg/L (25.8 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Santa Maria?
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 CA4210011 (2026-06). Method: own measurement. California SWRCB Division of Drinking Water, EDT lab results, system CA4210011 · Outdated figure? Tell us