Water hardness in Manhattan
5.7 gpg moderately hard
Tap water in Manhattan is moderately hard: 5.7 gpg (97 mg/L · 5.4 °dH · 9.7 °fH).
Source: City of Manhattan Public Works CY2024 Water Quality Report (2024) · data checked 2026-10-20
Manhattan, Kansas, pumps groundwater from wells in the Big Blue River alluvial aquifer. The city's CY2024 report lists total hardness as CaCO3 at 97 ppm (5.7 gpg), which is moderately hard. The sample behind it is dated 2023, so the figure may be older than the report year. The CY2025 report should replace it when checked.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 5.7 gpg |
|---|
How Manhattan compares
- Tap water in Manhattan is 37 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 1037 of 1372 in the United States (1 = hardest); 24 % of these cities have softer water.
- In Kansas it is number 15 of 17 cities; the regional median is 8.4 gpg.
- Nearest city with clearly harder water: Topeka, 79 km away (9 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Manhattan
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 5 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H1 |
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 Manhattan water hard or soft?
It is moderately hard: 97 mg/L as CaCO₃ (5.7 gpg, 5.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Manhattan 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 Manhattan water?
5.7 gpg, equal to 5.4 °dH, 9.7 °fH or 97 mg/L calcium carbonate.
What dishwasher salt setting should I use in Manhattan?
For 97 mg/L (5.4 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Manhattan?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: City of Manhattan Public Works CY2024 Water Quality Report (2024). Method: figure published by the water supplier. City of Manhattan Public Works CY2024 Water Quality Report · Outdated figure? Tell us