奥道後第4－1号、第9号、第13号源泉集合タンク
Okudogo Springs No. 4-1, No. 9 and No. 13 Collection TankOperated by · 寿温泉
Mixed source
Sodium Chloride spring
- Sodium Na⁺
- salt's cation — pairs with chloride to make the water salty.
- Chloride Cl⁻
- table-salt anion — coats the skin and holds heat in.
- Smooth skindry, rough skin
- Recoveryfatigue, stress
A gentle alkaline simple thermal spring (pH 8.9), drawn not from a single wellhead but from a tank that pools three Okudogo wells — No. 4-1, No. 9 and No. 13. Mineralization is light at 0.37 g/kg, so the water is easy on the body, yet the alkalinity gives the slippery feel of Japan's beauty-water family and 51.4 mg/kg of metasilicic acid leaves skin noticeably smoother. The posted panel lists the water for cold sensitivity and peripheral circulation disorders alongside the simple-spring indications of autonomic nervous system instability, insomnia and depressed mood. The bath itself is reheated, served via recirculation and disinfected with a chlorine-based agent, and the same panel notes that a herbal bath additive (yakusō-yu) is mixed in for its fragrance.
Sampled at mixing tank·Analyzed Aug 15, 2023·愛媛県立衛生環境研究所
