温泉の利点と欠点
玉川温泉の湯は湯川を下るにつれて冷やされ、水中に溶けていた成分が固化し、北投石、硫黄、ケイ酸、重晶石などのさまざまな沈殿物になります。沈殿物は、「湯の花」と呼ばれる微細な結晶と非晶質固体を形成し、バスソルトとして使用するために収穫されます。
強酸性の温泉水は玉川温泉を人気の保養地にした一方で、この水は河川や下流にある稲田に悪影響を及ぼすことがあり、地元の人々はこの悪影響のことを「玉川毒」と呼んでいます。近くの田沢湖も酸性化の影響を受け、湖の魚のほとんどが姿を消しました。
これらの問題に対処するため、多摩川酸性水中和処理施設での水処理などの対策が実施されています。
The Benefits and Drawbacks of Hot Springs
The waters of Tamagawa Onsen become cooler as they mingle with the Yugawa river water, and the compounds previously dissolved in the hot-spring waters solidify into various precipitates, including hokutolite, sulfur, silicic acid, and barite. The precipitates form minute crystals and amorphous solids called yu-no-hana or “hot water flowers” that are harvested for use as bath additives.
While the highly acidic waters have made Tamagawa Onsen a popular health retreat, such waters can have a negative impact on rivers and rice farms located downstream, an effect that locals have dubbed “Tamagawa poison water.” Nearby Lake Tazawako has also been affected by acidification, leading to the disappearance of nearly all of the fish in the lake.
To combat these issues, countermeasures have been introduced, including treatment of the water at the Tamagawa Acidic Water Neutralization Treatment facility.
