杭州通报自来水异味调查情况：依规依纪依法对7名领导干部严肃问责

Group 1 - The core issue of water supply abnormalities in Yuhang District highlights significant shortcomings in public drinking water safety and emergency response mechanisms [1][2] - A joint investigation team was established, including local and provincial authorities, to analyze the causes of the water quality issues, which were linked to environmental factors and algal blooms [1][2] - The investigation revealed that the presence of sulfur compounds in the water was responsible for the unpleasant odors detected [1] Group 2 - The local water supply companies implemented measures such as water source switching and pipeline flushing, which inadvertently caused rust to dislodge from iron pipes, leading to discolored water [2] - A comprehensive inspection of all 33 water supply plants in Hangzhou confirmed that the treated water met national health standards [3] - Affected residents will receive free replacement of water purifier filters and a full waiver of water fees for July due to the supply issues [3]