Water hardness in Malibu
10.9 gpg very hard
Tap water in Malibu is very hard: 10.9 gpg (187 mg/L · 10.5 °dH · 18.7 °fH).
Source: LA County Waterworks District No. 29 (Malibu) 2025 CCR (2025) · data checked 2026-11-03
Range across supply zones: 137–280 mg/L.
2 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| gpg | mg/L | ||
|---|---|---|---|
| Jensen plant | 13.7 | 234 | very hard |
| Weymouth plant | 8.2 | 140 | hard |
Los Angeles County Waterworks District No. 29 buys treated water from the Metropolitan Water District, which blends Colorado River and State Water Project supplies. The 2025 report shows two treatment plants: Jensen at 189 to 280 mg/L and Weymouth at 137 to 142 mg/L. The published figure of 187 mg/L (10.9 gpg) is a median across them, so the water at your tap can be softer or harder depending on which plant feeds your street.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 10.9 gpg |
|---|---|
| Utility | Los Angeles County Waterworks District No. 29 (Malibu) |
How Malibu compares
- Tap water in Malibu is 21 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 573 of 1372 in the United States (1 = hardest); 58 % of these cities have softer water.
- In California it is number 138 of 336 cities; the regional median is 9.5 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 Malibu
| Brand | Setting for this water |
|---|---|
| Bosch | H03 |
| Miele | 10 °dH |
| AEG / Electrolux | 2 |
| Beko | 3rd |
| Hoover | S2 |
| 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 Malibu water hard or soft?
It is very hard: 187 mg/L as CaCO₃ (10.9 gpg, 10.5 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Malibu 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 Malibu water?
10.9 gpg, equal to 10.5 °dH, 18.7 °fH or 187 mg/L calcium carbonate.
What dishwasher salt setting should I use in Malibu?
For 187 mg/L (10.5 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Malibu?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: LA County Waterworks District No. 29 (Malibu) 2025 CCR (2025). Method: figure published by the water supplier. LA County Waterworks District No. 29 (Malibu) 2025 CCR · Outdated figure? Tell us