Water hardness in Rosemead
5.7 gpg moderately hard
Tap water in Rosemead is moderately hard: 5.7 gpg (97 mg/L · 5.5 °dH · 9.7 °fH).
Source: San Gabriel County Water District 2025 Consumer Confidence Report (2025) · data checked 2026-11-02
Range across supply zones: 17–200 mg/L.
San Gabriel County Water District reports a median hardness of 97.4 mg/L in its 2025 Consumer Confidence Report, with individual values from 17 to 200 mg/L. The wide spread suggests the district blends water from more than one source, though the report figures alone do not tell us the mix. Check which range applies at your tap before sizing a softener.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 5.7 gpg |
|---|---|
| Utility | San Gabriel County Water District |
How Rosemead compares
- Tap water in Rosemead is 37 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 1036 of 1372 in the United States (1 = hardest); 25 % of these cities have softer water.
- In California it is number 253 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
- 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 Rosemead
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 5 °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 Rosemead water hard or soft?
It is moderately hard: 97 mg/L as CaCO₃ (5.7 gpg, 5.5 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Rosemead 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 Rosemead water?
5.7 gpg, equal to 5.5 °dH, 9.7 °fH or 97 mg/L calcium carbonate.
What dishwasher salt setting should I use in Rosemead?
For 97 mg/L (5.5 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Rosemead?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: San Gabriel County Water District 2025 Consumer Confidence Report (2025). Method: figure published by the water supplier. San Gabriel County Water District 2025 Consumer Confidence Report · Outdated figure? Tell us