Water hardness in South Gate
13.4 gpg very hard
Tap water in South Gate is very hard: 13.4 gpg (229 mg/L · 12.8 °dH · 22.9 °fH).
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA1910152 (2026-04) · data checked 2026-10-19
Range across supply zones: 209–268 mg/L.
The South Gate figure comes from State Water Resources Control Board lab results for the city water department. The median of 19 results from 2021 to 2026, taken at 10 well points, is 229 mg/L as CaCO3 (13.4 gpg), with a range of 208.8 to 267.8 mg/L. That is very hard water, and the range is fairly narrow. Expect heavy scale on heaters and fixtures.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 13.4 gpg |
|---|---|
| Utility | South Gate-City, Water Dept. |
How South Gate compares
- Tap water in South Gate is 48 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 437 of 1372 in the United States (1 = hardest); 68 % of these cities have softer water.
- In California it is number 93 of 336 cities; the regional median is 9.5 gpg.
- Nearest city with clearly softer water: Bell Gardens, 4 km away (8.2 gpg).
- Nearest city with clearly harder water: Norwalk, 11 km away (17.6 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 South Gate
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 13 °dH |
| AEG / Electrolux | 3 |
| Beko | 4th |
| 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 South Gate water hard or soft?
It is very hard: 229 mg/L as CaCO₃ (13.4 gpg, 12.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in South Gate 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 South Gate water?
13.4 gpg, equal to 12.8 °dH, 22.9 °fH or 229 mg/L calcium carbonate.
What dishwasher salt setting should I use in South Gate?
For 229 mg/L (12.8 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in South Gate?
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 CA1910152 (2026-04). Method: own measurement. California SWRCB Division of Drinking Water, EDT lab results, system CA1910152 · Outdated figure? Tell us