Recently, in the Yuhang District of Hangzhou, Zhejiang Province, an unusual smell was detected in the tap water supply. There were rumors circulating online that someone had connected the water pipeline to the sewage pipe network. Authorities had been consistently debunking these claims, but the latest report brought in national-level experts to investigate, attributing the presence of the odors to sulfur compounds produced by anaerobic degradation of algae under specific natural climatic conditions. However, netizens continue to question this explanation, with some suggesting a direct link between sulfur compounds and feces. Official sources have been suppressing the spread of related information and have started taking action against individuals.
The Yuhang District government of Hangzhou issued a notice today (July 19) regarding abnormal odors in the tap water in parts of Renhe Street and Liangzhu Street. On July 16 at 8 o’clock, the Renhe Water Plant found anomalies in the water quality odor index. After switching water sources, the water quality was effectively controlled, ensuring the safety of the water leaving the plant.
According to the notice, an investigation team composed of national and provincial-level experts has preliminarily confirmed that the odor is caused by sulfur compounds generated by the anaerobic degradation of algae under specific natural climatic conditions. The specific reasons are still under further investigation, and the results will be timely released.
The notice also mentioned that there are many online rumors, particularly regarding “sewage,” and the police have taken legal actions against spreading such misinformation, urging the public not to believe or spread false information.
Prior to this, on the evening of July 16, residents of the Yuhang District in Hangzhou found that the water from their taps was yellow and emitted a foul odor. Following the incident going viral on social media, a netizen named “@豆米金金” claimed that there was a system malfunction in the dispatching system, leading someone to divert the sewage valve to the water supply network, causing a significant uproar. Local netizens expressed their disgust, stating, “It’s too disgusting. We used this water to cook, the whole family consumed it, the more I think about it, the more nauseous I feel, almost vomiting all the overnight food.”
On July 18, a police incident report purportedly issued by the Liangzhu Police Station of the Yuhang Branch circulated online, alleging that a senior executive of the Hangzhou Water Group, Mr. Liu, harbored resentment towards the company’s chairman since September 23, 2024, and diverted sewage to the water supply network in the main urban area.
However, on the same day, the Hangzhou Public Security Bureau dismissed this claim as false information. Netizens then questioned, “So what is the truth?”
Following the response from the Hangzhou Yuhang Water Group Holdings Co., Ltd. on the evening of July 16 and a subsequent statement on July 17, the company completed flushing of the various water pipes and secondary water tanks after restoring normal operations at the Renhe Water Plant on July 16. The Water Group confirmed that the water quality in Renhe Street and Liangzhu Street had been restored, and users could resume normal usage. The company also announced a reduction of 5 tons of water fees for each household in July.
After the latest announcement from Hangzhou authorities on the afternoon of July 19, the news regarding the “official report on the abnormal odor in Yuhang tap water” quickly trended as the top topic on Weibo. Netizens continued to express skepticism:
“Reminds me of the Wuxi Taihu Lake blue-green algae incident.”
“Regardless of whether algae can produce odors in the Hangzhou tap water incident, the water plant should have a complete mechanism to remove them. If a widespread odor occurs, it indicates a failure or neglect in the water plant’s purification system. The responsible entities must be thoroughly investigated, and the public cannot be appeased with just a simple ‘natural cause’ explanation.”
“I don’t believe this explanation because it’s too abstract. If the reason is clear, explain precisely where, what specifically caused the water to turn yellow, instead of using chemical terms that others may not understand.”
“Algae: because they can’t talk back.”
“The water plant didn’t filter the water before giving it to the people, did they?”
“Where did the algae come from? If it’s untreated at the source? If the algae were filtered out, where did they come from then?”
“Don’t blame everything on the weather or the heavens. Be careful, the gods are watching.”
“If feces are being mistaken for algae, why can’t they take the public’s concerns seriously? If something is wrong, admit the mistake in your work. Is that so difficult?”
“Well, ‘natural cause,’ it makes sense. It’s normal for water to smell bad, with no human or management issues. Everyone, drink up!”
“They’ve been investigating for so long just to find new wording.”
“It’s pouring down rain of excrement and they’re still stirring things up!”
In response to the officials’ explanation that “the odor is caused by sulfur compounds produced by the anaerobic degradation of algae under specific natural climatic conditions,” a netizen mentioned, “Anaerobic fermentation is the utilization of organic waste (such as straw, manure, kitchen waste, municipal sludge, expired food, industrial organic waste, etc.) through anaerobic digestion by microorganisms to produce combustible gas, namely biogas.”
There’s been a viral discussion online about a netizen’s analysis of the direct relation between sulfur compounds and feces.
Some netizens shared feedback, saying, “Videos on similar topics have been removed!”