In the drinking water distribution pipeline system, tap water quality was regulated by several biotic and abiotic factors, which can threat to the health of consumers. Stagnation is inevitable in the water distribution pipeline. However, the combined effects of seasonal changes and stagnation on tap water quality are not well understood. Here, we investigated the seasonal variations in the chemical and biological quality of water after overnight stagnation for a period of one year. The results showed that the tap water quality deteriorated after overnight stagnation, with up to a 2.7-fold increase in the total iron concentrations. The total bacterial cell concentrations increased by 59–231% after overnight stagnation. The total cell and cell-bound adenosine triphosphate (ATP) of the stagnant water samples peaked in summer. In addition, Biolog analysis showed that the microbial metabolic activities of microbes were higher in spring. The bacterial community based on Illumina Miseq DNA sequence analysis found that Proteobacteria dominated the drinking water bacterial communities. The bacterial community structure varied significantly among different season, where the diversity and richness of the bacterial communities were much higher in spring. Structural equation modeling (SEM) was constructed to determine the correlations between bacterial metabolic functions and the community structure. The redundancy analysis (RDA) indicated that the residual chlorine played a critical role in the construction of the bacterial community. Altogether, the overall findings from the present work provide novel insights into how the quality of tap water quality impacted by the seasonal changes and overnight stagnation.

在饮用水分配管道系统中，自来水水质受到几种生物和非生物因素的调节，这可能威胁到消费者的健康。供水管道中不可避免地会出现停滞。然而，人们对季节性变化和停滞对自来水水质的综合影响尚不十分了解。在这里，我们调查了过夜停滞一年后水的化学和生物质量的季节性变化。结果表明，自来水水质在一夜之间停滞后恶化，总铁浓度提高了2.7倍。过夜停滞后，总细菌细胞浓度增加了59–231％。积水样品的总细胞和细胞结合的三磷酸腺苷（ATP）在夏季达到峰值。此外，生物学分析表明，春季微生物的代谢活性较高。基于Illumina Miseq DNA序列分析的细菌群落发现，变形杆菌主导了饮用水细菌群落。细菌群落结构在不同季节之间存在显着差异，春季的细菌群落多样性和丰富度要高得多。构建了结构方程模型（SEM），以确定细菌代谢功能与群落结构之间的相关性。冗余分析（RDA）表明，残留的氯在细菌群落的构建中起着关键作用。共，