Objective To explore the sanitary conditions of direct-drinking water pipeline system in residential area of Yangpu District. In order to strengthen the management of direct-drinking water, provide the basis for protection of drinking safety.
Methods Questionnaire survey was conducted on the residents using direct-drinking water pipeline system in 9 residential areas in 2008. Source water, finished water, backflow of water and piped water from these residential areas were sampled to assess water quality.
Results In the 9 assessed redisent areas, water-making apparatuses of six residential areas were in the basements. Ozone was used to disinfect the direct-drinking water in all apparatuses. Water quality was monitored by themselves two to four times every month. One or two persons were in charge of daily maintenance. Water quality test of direct-drinking water showed that the value of the indices, such as turbidity, pH value, total hardness and so on, were much lower than those of tap water (P<0.05). Total number of bacteria in part of piped water and backflow of water was positive (3-42 CFU/mL).
Conclusion The quality of direct-drinking water is better than that of tap water, but sanitation management system, daily maintenance and disinfection measures have limitations, which are easy to cause secondary pollution.
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