Investigation on Cause of an Unqualified Dedicated Drinking Water System and its Correction Measures

Objectives  To investigate the basic cause of an unacceptable drinking-water incident happened in a dedicated drinking water system and make corrections to realize qualified water supply.

Methods  Through analyzing all surveillance data, the indicators on turbidity, chrominance, chemical oxygen demand (COD_Mn) and total bacterial count were selected as necessary ones for investigation and correction. Conducting a field investigation on deep purification steps and daily maintenances.

Result  The direct and doubtful steps which causing drinking water unacceptable were found. The quality of end water met the requirements of "sanitary standards for dedicated drinking water"(DB 32/761-2005) after treatment with sand leach, carbon filter and ultraviolet disinfection.

Conclusions  Municipal water supply can meet the requirements of "sanitary standards for dedicated drinking water" (DB 32/761-2005) after corrections being made. In order to offer qualified dedicated drinking water all the time, daily maintenance must be done according to the requirements and further supervision must be conducted by relevant health departments.