Monitoring results of urban drinking water quality in Jiangxi Province, China, 2016—2020

Objective To investigate the basic situation and changing trend of urban drinking water quality in Jiangxi Province, China, in 2016-2020, and to provide a basis for strengthening drinking water safety management.

Methods From 2016 to 2020, water quality monitoring was conducted in 1439 monitoring sites in 11 district-level cities and 98-100 districts and counties in Jiangxi Province, which covered the finished water and terminal water from municipal centralized water supply and centralized water supply with self-built facilities, as well as secondary water supply. Water samples were collected twice a year in wet season and dry season, respectively. Water quality was detected and evaluated according to the Standard Examination Method for Drinking Water (GB/T 5750-2006) and the Standards for Drinking Water Quality (GB 5749-2006), respectively.

Results From 2016 to 2020, the overall qualified rate of samples was 92.47% for urban drinking water in Jiangxi Province, with a gradual increase year by year (χ_trend²=322.92, P < 0.05), and there was no significant difference in the overall qualified rates of water samples between the wet season and the dry season (χ²=3.81, P >0.05). Water samples had a significantly higher qualified rates in municipal centralized water supply than those in centralized water supply with self-built facilities (χ²=290.79, P < 0.05). For municipal centralized water supply, terminal water had the highest qualified rate, followed by finished water and secondary water supply(χ²=164.25, P < 0.05), while for centralized water supply with self-built facilities, there was no significant difference in the rate of reaching the standard between finished water and terminal water (χ²=1.30, P >0.05). There was a significant difference in the qualified rates between surface water source and underground water source (χ²=9.03, P < 0.05), and the qualified rates of manganese and free chlorine of samples from underground water source were significantly lower than those from surface water source (P < 0.05). The water samples treated with coagulation, precipitation, filtration, and disinfection and those treated with disinfection only by water supply units had significantly higher qualified rates than those treated with precipitation and filtration or without any treatment (P < 0.05 after adjustment). Microbiological indicators and disinfectant indicators were the main influencing factors for urban drinking water quality in Jiangxi Province.

Conclusion There is a gradual increase in the rate of reaching the standard for urban drinking water in Jiangxi Province, while it is still necessary to strengthen the sanitation supervision of centralized water supply through self-built facilities and secondary water supply, enhance water quality treatment, and emphasize water source disinfection and purification, with a focus on microbiological indicators and disinfectant indicators, so as to prevent water-borne infectious diseases.