[Study on the characteristics of combined sewer overflow from the high density residential area in Shanghai].

The urban non-point pollution has become main pollution resource of urban water bodies of Shanghai. Character of combined sewer overflow from watershed SA in Shanghai was studied, and the correlation of influence factors to the EMCs of overflows was discussed. It is found that the EMCs of COD, BOD, SS, NH3-N, TN, TP are 614 mg/L, 208.5 mg/L, 684 mg/L, 17.6 mg/L, 29.8 mg/L, 3.0 mg/L respectively, and the values obtained herein are much higher than the documented data from other countries. From the probability plot of the EMCs, it is found that the BOD has the best fitness for lognormal distribution; and correlation between the EMCs of COD, SS and the ratio of antecedent dry weather time to rain duration is quite good.