Fukuichi

A blended source drawing on the Nishizawa-no-Yu wells No. 1, 3 and 4. It carries no therapeutic spring-quality name: the posted analysis states the water qualifies as an onsen under Japan's Hot Spring Law purely because its metasilicic acid content clears the statutory limit at 66.1 mg/kg — the same silica that puts it in Japan's beauty-water family, leaving skin smooth rather than coated. Mineralization is light at roughly 0.24 g/kg and the pH sits at 6.0, so the water reads as mild and low-irritation. The source itself is a cold mineral spring at 15.5 °C, so it is reheated for bathing, held at temperature by recirculation and disinfected with a chlorine agent; no water is added except in emergencies.

Analyzed Sep 19, 2008·群馬県薬剤師会環境衛生試験センター