原げん水すい

noun

raw water; untreated water

Refers to water in its natural state before any purification or treatment process, often used in contexts like water treatment plants or environmental discussions.

• 浄じょう水すい場じょうでは、原げん水すいをろ過かして飲のみ水みずにしている。

  At the water purification plant, raw water is filtered and turned into drinking water.