Objectives To investigate the hygienic status of urban drinking water and the epidemiological characteristics of water-borne diseases.

Methods Monitoring the quality of water samples selected in 31 monitored points from Neijiang city municipal water supplies and self-owned water plants; and collecting the death-related information related to water-borne diseases, within the context of cancer and chronic non-communicable disease.

Results The total qualified rate of all kinds of municipal water supplies was 97.89%; the qualified rate of peripheral water was 99.26%, the qualified rate of factory water was 77.78%, and the qualified rate of secondary water was 66.67%. The ineligible items were mainly pH, oxygen consumption, chlorine residues, total coliform and the number of total colonies. Since the total qualified rate of various types of self-built water factories was 75%, the qualified rate of factory water was 83.33%, and the qualified rate of peripheral water was 70.83%. The unqualified items were mainly chloroform, turbidity, oxygen consumption, visible solids, iron and ammonia nitrogen. There were 2 080 water-borne disease patients being monitored. The incidence of water-borne disease in 2008 was 36.18/10⁶ and concentrated in September to November, and the incidence in 2009 was 31.87/10⁶ and concentrated in March and April. The total death related to cancer and non-communicable disease was 1 063 cases.

Conclusions The quality of municipal water supplies was good in general, but the quality of water from the water fa ctory should be improved. It is necessary to enhance water management and monitoring, to guide self-built fa ctories to improve water treatment processes to improve water quality. The investigation on water-borne diseases prompted the epidemiological significance of prevention and control of communicable diseases.