Water Pollution Control Measures and Test Reporting Management Regulations Article 66

If an enterprise or sewage system has difficulty in installing independent and exclusive cumulative water measuring facilities in accordance with the Regulations, they may conduct measurement using any other measuring facilities or method that is able to indicate the water volume, subject to approval from the competent authority.If the facilities in the preceding paragraph generate records in a continuous and automatic way, the enterprise or sewage system shall record the water volume based on the specifications and frequencies of the facilities. If the facilities do not generate records in such a way, the cumulative water volume reading shall be recorded daily and preserved for five years for reference.
中文原文 水污染防治措施及檢測申報管理辦法第66條
事業或污水下水道系統依本辦法規定設置之獨立專用累計型水量計測設施,有設置困難,經主管機關同意者,得以足以證明水量之計測設施或計量方式為之。
前項設施為連續自動記錄者,事業或污水下水道系統應依計測設施之設計規格及頻率記錄;非為連續自動記錄者,應每日記錄其累計水量讀數,並保存五年,以備查閱。

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