Photo: Screenshot of CCTV News

The leakage of waste water in a power plant in Tieling, Northeast China's Liaoning Province, is being addressed under the guidance of national and provincial expert groups. The contaminated water is expected to meet safety standards before flowing into sea. 

The concentration of ammonia nitrogen in the leaked water is about 120 milligrams per liter while the maximum approved level of concentration of water pollutants is 10 milligrams per liter, according to water discharge standards in Liaoning, Central China Television reported on Sunday. 

A long term accumulation of ammonia nitrogen can lead to water eutrophication, a process that results from the buildup of nutrients that stimulates the growth of algae. 

The leakage, which was first reported by authorities on Wednesday, happened when the power plant was handling ashes from the burning of coal. Water is used to flush ash and transport it to an ash field by pipeline, the impurities in the ash slurry are deposited in the ash field and the clarified water is returned to the power plant for recycling, said the report. 

The plant piled up the ash in the field which produced a large amount of waste water, it said. The exact amount of contaminated water is unknown. 

The leaked waste water was reported to have flowed into Liaohe River which runs in the south of northeastern China and flows into the Bohai Sea on the east coast of the Chinese mainland. 

Environmental emergency response authorities in Shenyang, capital of Liaoning Province and close to Tieling, have been closely monitoring water quality of the Liaohe River. Water supply companies in the city are measuring the quality of the water every two hours. 

The national expert group of environmental emergency response arrived in Tieling on Tuesday. The measures adopted to decrease the environmental impact include blocking the contaminated water and releasing water to reduce pollution.

The water quality in Tieling has improved and it is expected that the polluted water will reach the required standards before reaching the sea. 

The owner of the power plant in question, the Liaoning Huadian Tieling Power Generation enterprise, is a joint-stock enterprise of the state-owned Liaoning Energy Group.