A 4-km stretch of a river in north China's Hebei province turned red due to excessive levels of iron ion and industrial waste, authorities said today.
Untreated industrial sewage, especially from local iron and steel plants, seriously polluted the Zhongting River in Shengfang town.
The stretch of the river has run red in recent days due to iron ions and rising temperatures, an official said.
Since 2005, however, the city has treated the river, but iron ions remain in the silt, the official said.
Currently, the water in the river comes from rainfall and treated industrial sewage, said the government.
The river is a flood control waterway that passes the cities of Langfang and Bazhou before emptying into the Haihe river in Tianjin municipality.
It is not a drinking-water source.
It was dammed several years ago at the border area between Bazhou and Tianjin to prevent water flowing into Tianjin, state run Xinhua news agency reported.
Environmental authorities will carry out regular water quality inspections and ensure industrial waste is discharged after being treated, the official said.
Experts have collected samples of the silt for further tests to help with treatment plans, said the official.
