The mayor of Hezhou city in south China's Guangxi Zhuang Autonomous Region on Tuesday apologized to residents for a river pollution case in a public statement.
Bai Xi said in the written apology that loopholes in his government's environmental protection and management work have led to river contamination.
He said he and his government felt sorry that the river pollution not only does harm to the city's reputation, but also causes losses and inconvenience for local residents.
Bai added that he has also apologized to residents whose lives were affected by the polluted river in neighboring cities and counties.
The pollution was discovered after local authorities in Fengkai County in Guangdong Province, which neighbors Guangxi, said on Saturday that water in a section of the Hejiang River had been tainted by upstream pollution.
The county warned local tap water plants and residents living in the lower reaches of the Hejiang and Xijiang rivers to avoid drinking water or consuming products derived from the river.
Cadmium and thallium levels at a reservoir located on the river were four times and 1.3 times the recommended level, respectively, as of Monday, according to Yang Zhongxiong, vice head of Hezhou's environmental protection bureau.
The Hejiang River winds across Guangxi before emptying into the Xijiang River in Guangdong. Xijiang is a major waterway in Guangdong.
A mining company in the city of Hezhou in the Guangxi Zhuang Autonomous Region is believed to have used illegal production processes that resulted in excessive thallium and cadmium pollution in the Hejiang River, the Hezhou municipal government said in a press release on Monday.
The company's head, a man surnamed Gong, has been taken into police custody, said Li Weizhang, vice mayor of Hezhou.
Gong is suspected of adding indium production facilities to his iron ore processing plant without approval.
Indium refinement produces effluents that contain thallium and cadmium, both of which are toxic.