Total amount of discharged wastewater in 2004 was 48.24 billion tons, of which the discharged industrial effluent was 22.11 billion tons and domestic sewage 26.13 billion tons. The discharged amount of COD was 13.392 million tons, of which the amount of industrial COD was 5.097 million tons and domestic COD 8.295 million tons. The discharged amount of ammonia nitrogen was 1.33 million tons, of which 422,000 tons were from industries and 908,000 tons from domestic source.

In 2004, 90.7% of the discharged industrial effluent met discharging standard, 1.5 percentage points higher than that of 2003. Among them, 91.9% of major enterprises met effluent discharging standard, 1.4 percent points more than that of 2003. In the order of 80.6% of non-major enterprises met industrial effluent discharging standard, 2.9 percentage points up than that of the previous year.