Water hardness in Manteca
10.1 gpg hard
Tap water in Manteca is hard: 10.1 gpg (174 mg/L · 9.7 °dH · 17.4 °fH).
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA3910005 (2024-05) · data checked 2026-10-19
Range across supply zones: 167–180 mg/L.
The Manteca figure comes from State Water Resources Control Board lab results for the City of Manteca system. It rests on only 2 results from one well, between 2021 and 2024: a median of 173.5 mg/L as CaCO3 (10.1 gpg), within a range of 167 to 180 mg/L. Two samples are thin evidence. Check the city's current water report before choosing a softener.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 10.1 gpg |
|---|---|
| Utility | Manteca, City Of |
How Manteca compares
- Tap water in Manteca is 12 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 619 of 1372 in the United States (1 = hardest); 55 % of these cities have softer water.
- In California it is number 153 of 336 cities; the regional median is 9.5 gpg.
- Nearest city with clearly softer water: Stockton, 19 km away (3.4 gpg).
- Nearest city with clearly harder water: Patterson, 36 km away (22.7 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Fast scale on taps, shower screens and kettle; white spots on glassware.
- Water heater: efficiency loss and element failures within years if unprotected.
- Dry skin and dull hair after showering are common.
- Softener recommended; jug or reverse osmosis for drinking.
How much salt will you use for softening?
Recommended, especially with a heater or boiler: scale cuts efficiency and shortens its life.
Descale a coffee machine or kettle about every 2 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Manteca
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 10 °dH |
| AEG / Electrolux | 2 |
| Beko | 3rd |
| Hoover | S1 |
| 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 Manteca water hard or soft?
It is hard: 174 mg/L as CaCO₃ (10.1 gpg, 9.7 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Manteca 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 Manteca water?
10.1 gpg, equal to 9.7 °dH, 17.4 °fH or 174 mg/L calcium carbonate.
What dishwasher salt setting should I use in Manteca?
For 174 mg/L (9.7 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Manteca?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA3910005 (2024-05). Method: own measurement. California SWRCB Division of Drinking Water, EDT lab results, system CA3910005 · Outdated figure? Tell us