2020 surface water quality ranking of Anhui released

The Department of Ecology and Environment of Anhui recently released the 2020 surface water quality ranking of 16 prefecture-level cities in the province, with Huangshan, Chizhou and Tongling ranking the top three. Tongling led the province in improving its surface water quality by 12.27%.

The rankings are determined by the size of the water quality index, with the lower the index indicating the better quality of surface water. 21 indicators were taken into account when evaluating water quality, including pH, dissolved oxygen, permanganate index, biochemical oxygen demand, and ammonia nitrogen.

The ranking table reflects the decline, flat and improvement of surface water quality in each city compared with the same period of last year through the change rate of water quality index. A value greater than 0 represents a decline, a value equal to 0 represents a flat and a value less than 0 represents an improvement. Statistics show that the change rates of water quality index in all other cities are less than 0, except that the change rate in Maanshan City is 0.76%. The improvement of surface water quality in Tongling, Chizhou and Bengbu ranks the top three in the whole province.