Hygienic Evaluation on New Secondary Water Supply in Guangzhou

Objectives To investigate and understand the sanitary status of new secondary water supplies in Guangzhou, and provide related technologies and measures for the hygienic safety of drinking water from the new secondary water supplies constructed in Guangzhou in 2013.

Methods Investigating the new secondary water supplies and testing the quality of water samples according to related national standards and norms.

Results The main hygienic defects in 144 new secondary water supplies investigated were not locking the entrance of water tank, and too close of water tank to the ceiling of room. The quality of 144 water samples in 117 tested water samples was good and the qualified rate was 81.3%. There was no significant difference on the qualified rate between the secondary water and the terminal water in the city (P>0.05). The major unqualified items were total bacterial counts, turbidity and iron, and their qualified rates were 84.0%, 98.6% and 98.6%, respectively.

Conclusions There were some hygienic problems on new secondary water supplies in Guangzhou. Strengthening a participation of multi-department and multi-stage cooperation to construct standard hygienic management, supervision and inspection is needed.