Refers to water containing minerals, often from a natural spring. Synonymous with ミネラルウォーター, though 鉱泉水 may carry a slightly more technical or formal tone.
See also: ミネラルウォーター
The mineral water in this region is rich in minerals.
鉱泉水を飲むと健康に良いと言われている。
It is said that drinking mineral water is good for your health.