Water hardness in St. Joseph
13 gpg very hard
Tap water in St. Joseph is very hard: 13 gpg (222 mg/L · 12.4 °dH · 22.2 °fH).
Source: Missouri American Water, water quality report (St Joseph) (2025) · data checked 2026-10-20
Range across supply zones: 210–222 mg/L.
Missouri American Water pumps St. Joseph's water from many vertical wells and a horizontal collector well in the Missouri River alluvium. River sand and gravel releases calcium and magnesium into the water, giving 222 mg/L CaCO₃ (210–222 mg/L). Hard water means scale on glass and in heaters.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 13 gpg |
|---|---|
| Utility | Missouri American Water |
How St. Joseph compares
- Tap water in St. Joseph is 43 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 455 of 1372 in the United States (1 = hardest); 67 % of these cities have softer water.
- In Missouri it is number 10 of 32 cities; the regional median is 10.3 gpg.
- Nearest city with clearly softer water: Parkville, 61 km away (9.2 gpg).
- Nearest city with clearly harder water: Kansas City, 74 km away (16.4 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 St. Joseph
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 12 °dH |
| AEG / Electrolux | 3 |
| Beko | 3rd |
| 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 St. Joseph water hard or soft?
It is very hard: 222 mg/L as CaCO₃ (13 gpg, 12.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in St. Joseph 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 St. Joseph water?
13 gpg, equal to 12.4 °dH, 22.2 °fH or 222 mg/L calcium carbonate.
What dishwasher salt setting should I use in St. Joseph?
For 222 mg/L (12.4 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in St. Joseph?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Missouri American Water, water quality report (St Joseph) (2025). Method: figure published by the water supplier. Missouri American Water, water quality report (St Joseph) · Outdated figure? Tell us