Analysis of the monitoring results of rural drinking water in Banan district, Chongqing, China, 2018—2022

Objective To analyze the sanitary situation of rural drinking water and the change in drinking water quality in Banan district, Chongqing, China, from 2018 to 2022, and to provide a theoretical basis for management and planning improvement of local water quality.

Methods The monitoring data of rural drinking water in Banan district from 2018 to 2022 were collected and sorted out, and the qualified rate was determined according to the Standards for Drinking Water Quality (GB 5749-2006). The chi-square test and Fisher's exact test were used to compare the qualified rates of rural drinking water in Banan district between different years, different water periods, different water samples, different water source types, and different disinfection methods (the level of significance, α=0.05).

Results A total of 460 rural drinking water samples were monitored in Banan district from 2018 to 2022, and 374 were qualified, with a qualified rate of 81.30%. The qualified rate of drinking water differed significantly in the five years (χ²=13.05, P=0.011), but there was no significant upward trend (P_trend=0.083). The qualified rates of drinking water showed no significant differences between different water periods and water sample types (P > 0.05), but was significantly different between different water source types (χ²=16.89, P < 0.001) and different disinfection methods (χ²=12.22, P=0.002). During the wet season, the qualified rate of drinking water from river water sources (96.88%) was significantly higher than that from reservoirs (85.06%) and other types of water sources (ditches, ponds, and deep wells, 54.17%; χ²=14.52, P < 0.001). In the dry season, the qualified rate of drinking water disinfected with liquid chlorine and sodium hypochlorite was significantly higher than that of water sources disinfected with chlorine dioxide (χ²=14.03, P < 0.001). For the same water source, the qualified rate of water disinfected with chlorate-based chlorine dioxide was significantly higher during the dry season (90.63%) than during the wet season (81.25%; χ²=4.66, P=0.031). Among all the tested indices, the qualified rate of the microbial index was the lowest at 83.26%.

Conclusion The monitoring result of rural drinking water in Banan district of Chongqing during 2018 to 2022 indicate the need for improvement in sanitary safety, and the microbial index is the main influencing factor. The region should strengthen the supervision and protection of rural drinking water from the source to the tap, fundamentally increasing the quality of drinking water to ensure the health of residents.