Water hardness in El Monte
15.2 gpg very hard
Tap water in El Monte is very hard: 15.2 gpg (260 mg/L · 14.6 °dH · 26 °fH).
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA1910038 (2026-06) · data checked 2026-10-19
Range across supply zones: 193–364 mg/L.
The El Monte figure comes from State Water Resources Control Board lab results for the city's own water department, which serves only part of El Monte. The median of 157 results from 2021 to 2026 is 260 mg/L as CaCO3 (15.2 gpg), with a range of 192.8 to 364 mg/L. Other suppliers cover the rest, so check which one bills you. This is very hard water.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 15.2 gpg |
|---|---|
| Utility | El Monte-City, Water Dept. |
How El Monte compares
- Tap water in El Monte is 68 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 353 of 1372 in the United States (1 = hardest); 74 % of these cities have softer water.
- In California it is number 66 of 336 cities; the regional median is 9.5 gpg.
- Nearest city with clearly softer water: San Gabriel, 7 km away (5.8 gpg).
- Nearest city with clearly harder water: Monterey Park, 10 km away (22.2 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 El Monte
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 15 °dH |
| AEG / Electrolux | 3 |
| 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 El Monte water hard or soft?
It is very hard: 260 mg/L as CaCO₃ (15.2 gpg, 14.6 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in El Monte 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 El Monte water?
15.2 gpg, equal to 14.6 °dH, 26 °fH or 260 mg/L calcium carbonate.
What dishwasher salt setting should I use in El Monte?
For 260 mg/L (14.6 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in El Monte?
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 CA1910038 (2026-06). Method: own measurement. California SWRCB Division of Drinking Water, EDT lab results, system CA1910038 · Outdated figure? Tell us