Chang, C.-L.C.-L.ChangYu, Y.-H.Y.-H.YuChien, I.-C.I.-C.ChienTung, H.-H.H.-H.TungHSIN-HSIN TUNG2021-02-042021-02-042020https://www.scopus.com/inward/record.url?eid=2-s2.0-85092251728&partnerID=40&md5=d395955af2c48d9b901d670cd9472db8https://scholars.lib.ntu.edu.tw/handle/123456789/546792Indirect premise plumbing is a common practice for water distribution in Taiwan. However, the extended water residence time in indirect premise plumbing system may encourage bacterial regrowth. In addition, natural organic matter or sediments in roof top storage tank/tower may also react with residual chlorine and generate additional disinfection byproducts (DBPs). A year long water monitoring task was conducted in a building with indirect water supply system including concrete roof top storage tank. The roof top storage tank was cleaned twice in the sampling period follow the Taiwan EPA's recommendation. Chemical parameters, heterotrophic plate counts (HPC), and planktonic microbiome from both tank influents and effluents were analyzed intermittently before and after storage tank cleaning. The results showed that after cleaning, the chlorine decay, and trihalomethanes formation were decreased in the tank effluent. However, HPCs were increased in the beginning along with planktonic microbial population changes. After tank cleaning, it will take 2 to 3 weeks before the microbial population was stabilized again. © 2020, Chinese Institute of Civil and Hydraulic Engineering. All right reserved.Disinfection byproduct; Heterotrophic plate count; Indirect water supply; Next generation sequencing[SDGs]SDG6Chemical analysis; Chemical cleaning; Chlorine; Plumbing; Residence time distribution; Roofs; Water quality; Water supply; Water supply systems; Water tanks; Chemical parameters; Disinfection byproducts; Heterotrophic plate counts; Microbial populations; Natural organic matters; Trihalomethanes formations; Water distributions; Water residence time; Effluentsjournal article10.6652/JoCICHE.202005_32(3).00032-s2.0-85092251728