Water hardness in Folsom
1.5 gpg soft
Tap water in Folsom is soft: 1.5 gpg (25 mg/L · 1.4 °dH · 2.5 °fH).
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA3410014 (2026-07) · data checked 2026-10-19
Range across supply zones: 18–31 mg/L.
The Folsom figure comes from State Water Resources Control Board lab results for the main City of Folsom system, which treats Folsom Lake water from the American River. The median of 26 finished-water results from 2021 to 2026 is 25 mg/L as CaCO3 (1.5 gpg), with a range of 18 to 31 mg/L. This is very soft water. Scale is negligible, and a softener adds nothing for hardness.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 1.5 gpg |
|---|---|
| Utility | Folsom, City Of - Main |
How Folsom compares
- Tap water in Folsom is 84 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 1302 of 1372 in the United States (1 = hardest); 5 % of these cities have softer water.
- In California it is number 319 of 336 cities; the regional median is 9.5 gpg.
- Nearest city with clearly softer water: Auburn, 26 km away (0.9 gpg).
- Nearest city with clearly harder water: Citrus Heights, 13 km away (4.5 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Little or no limescale in kettles, water heaters or washing machines.
- Soap lathers easily; water does not dry skin or hair.
- Dishwasher: salt setting at minimum or off.
- No softener needed; a jug filter only changes taste.
How much salt will you use for softening?
No. Water this soft does not need softening.
Descale a coffee machine or kettle about every 6 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Folsom
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 1 °dH |
| AEG / Electrolux | 1 |
| Beko | 1st |
| Hoover | S0 |
| LG | H0 |
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 Folsom water hard or soft?
It is soft: 25 mg/L as CaCO₃ (1.5 gpg, 1.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Folsom 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 Folsom water?
1.5 gpg, equal to 1.4 °dH, 2.5 °fH or 25 mg/L calcium carbonate.
What dishwasher salt setting should I use in Folsom?
For 25 mg/L (1.4 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Folsom?
No. With soft water a softener adds nothing.
Source
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA3410014 (2026-07). Method: own measurement. California SWRCB Division of Drinking Water, EDT lab results, system CA3410014 · Outdated figure? Tell us