Water hardness in Rancho Palos Verdes
15.8 gpg very hard
Tap water in Rancho Palos Verdes is very hard: 15.8 gpg (271 mg/L · 15.2 °dH · 27.1 °fH).
Source: California Water Service Palos Verdes 2024 Water Quality Report (2024) · data checked 2026-11-02
Range across supply zones: 235–305 mg/L.
2 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| gpg | mg/L | ||
|---|---|---|---|
| Diemer plant (MWD wholesale) | 15.8 | 270 | very hard |
| Weymouth plant (MWD wholesale) | 15.9 | 272 | very hard |
Rancho Palos Verdes is served by California Water Service, which buys wholesale water from MWD. The 2024 report gives an average of 271 mg/L as CaCO3, with two zones ranging from 235 to 305 mg/L. All of that is very hard water. Scale on fixtures and appliances is common, and a softener is worth considering.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 15.8 gpg |
|---|---|
| Utility | California Water Service Palos Verdes (MWD wholesale) |
How Rancho Palos Verdes compares
- Tap water in Rancho Palos Verdes is 75 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 322 of 1372 in the United States (1 = hardest); 76 % of these cities have softer water.
- In California it is number 55 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 Rancho Palos Verdes
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 15 °dH |
| AEG / Electrolux | 4 |
| Beko | 4th |
| Hoover | S2 |
| LG | H3 |
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 Rancho Palos Verdes water hard or soft?
It is very hard: 271 mg/L as CaCO₃ (15.8 gpg, 15.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Rancho Palos Verdes 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 Rancho Palos Verdes water?
15.8 gpg, equal to 15.2 °dH, 27.1 °fH or 271 mg/L calcium carbonate.
What dishwasher salt setting should I use in Rancho Palos Verdes?
For 271 mg/L (15.2 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Rancho Palos Verdes?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: California Water Service Palos Verdes 2024 Water Quality Report (2024). Method: figure published by the water supplier. California Water Service Palos Verdes 2024 Water Quality Report · Outdated figure? Tell us