[en] Water for Injection (WFI) used in production of Technetium-99m (Tc-99m) bound to stringent specifications in order to comply with Good Manufacturing Practice (GMP) requirements. The WFI should meet British Pharmacopoeia (BP) and United States Pharmacopoeia (USP) grade specifications. The goal of the study is to test the WFI system whether it is running optimally and operating normally after undergo some repairs and maintenance s. Physical appearance, pH, total organic carbon and conductivity test is done in order to evaluate the water quality which consequently implies indirectly the condition of the water system. Results have shown that purified water from sampling point 4 and WFI from sampling point 20 indirectly indicate possible problems in the water system. Overall the WFI system running normally and optimally except for sampling point 4 and 20 which need further investigation. (author)