Water hardness in Olathe
10.5 gpg very hard
Tap water in Olathe is very hard: 10.5 gpg (180 mg/L · 10.1 °dH · 18 °fH).
Source: City of Olathe 2023 Water Quality Report (2023) · data checked 2026-10-19
The City of Olathe reports total hardness as CaCO3 of 180 mg/L (10.5 gpg) in its 2023 water quality report. This comes from one sample taken on 26 April 2022, so it is a single reading and not an annual average. Water at this level is hard, and scale on kettles and water heaters is likely. A newer city report may give a different figure.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 10.5 gpg |
|---|---|
| Utility | City of Olathe Water Utilities |
How Olathe compares
- Tap water in Olathe is 16 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 591 of 1372 in the United States (1 = hardest); 56 % of these cities have softer water.
- In Kansas it is number 6 of 17 cities; the regional median is 8.4 gpg.
- Nearest city with clearly softer water: Lenexa, 11 km away (7.9 gpg).
- Nearest city with clearly harder water: Kansas City, 31 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 Olathe
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 10 °dH |
| AEG / Electrolux | 2 |
| 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 Olathe water hard or soft?
It is very hard: 180 mg/L as CaCO₃ (10.5 gpg, 10.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Olathe 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 Olathe water?
10.5 gpg, equal to 10.1 °dH, 18 °fH or 180 mg/L calcium carbonate.
What dishwasher salt setting should I use in Olathe?
For 180 mg/L (10.1 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Olathe?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: City of Olathe 2023 Water Quality Report (2023). Method: own measurement. City of Olathe 2023 Water Quality Report · Outdated figure? Tell us