KC has some of the hardest water in the US, new survey shows. What it means
Leaf Home ranked Kansas City fifth among U.S. cities in 2025 for the worst hard water conditions, meaning excess minerals in usable water.
Hard water circulating in the water system isn’t harmful, but it can make home repairs more expensive.
This is Leaf Home’s list of the top 10 cities for hard water:
- Midland, TX: 400-600 mg/L
- Las Vegas, NV: 300+ mg/L
- San Antonio, TX: 280-300 mg/L
- Indianapolis, IN: 250+ mg/L
- Kansas City, MO: 250-300 mg/L
- Phoenix, AZ: 200-250 mg/L
- Riverside, CA: 200-250 mg/L
- Minneapolis, MN: 170-250 mg/L
- Tampa, FL: 150-300 mg/L
- Salt Lake City, UT: 150-250 mg/L
How hard water is measured
Water hardness measures extra minerals, like calcium and magnesium, in milligrams per liter (mg/L) of calcium carbonate (CaCO₃), said the U.S. Geological Survey. The measurement is classified into four categories:
- 0-60 mg/L – Soft
- 61-120 mg/L – Moderately Hard
- 121-180 mg/L – Hard
- 180+ mg/L – Very Hard
Hard water isn’t dangerous for consumption, but it can be a major cause of household issues like limescale buildup, plumbing and appliance inefficiencies, and costly maintenance, said Leaf Home, a home improvement company.
Indicator signs of hard water can range from limescale stains to causing soap to not lather, said Leaf Home.
Water hardness measurements are classified as secondary standards by the Environmental Protection Agency, meaning the guidelines are non-enforceable, said Kansas City’s water quality report. The secondary standard constituents may cause cosmetic effects such as skin or tooth discoloration or aesthetic effects such as taste, odor, or color in drinking water, the report said.
Water hardness levels in Missouri River, Kansas City
The U.S. Geological Survey found that the Missouri River had water hardness levels ranging from 250 to 300 milligrams per liter, which is considered very hard.
According to KC Water’s 2024 water quality report, the water hardness levels range from 84.6 to 136 mg/L, last measured in 2021. In 2020, the levels were at 140 mg/L.
“Over the last year, KC Water has had an average hardness of 114.87 mg/L for the treated water that is sent to customers,” said Jackson Overstreet, public information officer for the KC Water Department.
Since it depends on the natural minerals in the area, hardness levels vary widely throughout the U.S, but it affects 85% of U.S. homes, according to the Water Quality Program from Cornell University’s College of Human Ecology.
