Sewerage Act Article 24

The sewerage institution may dispatch its personnel with identification documents to examine sewer users' drainage facilities and inspect water flow rate and water quality.
中文原文 下水道法第24條
下水道機構,得派員攜帶證明文件檢查用戶排水設備、測定流量、檢驗水質。

English translation for reference only; the Chinese text prevails. Not legal advice.