About TAMAI Y
About Waterworks Bureau Osaka Municipal Government
About YAMADA K
About Waterworks Bureau Osaka Municipal Government
About MIYAUCHI K
About Waterworks Bureau Osaka Municipal Government
About Osaka and Its Technology
About water quality management
About かつら川
About Water quality control
About River pollution
About 淀川水系
About 水質保全
About 問題
About 調査