Statistical Design of Equalization Basins

The design of equalization basins is based on a statistical characterization of the influent rates of mass and fluid flow. The statistics required are the means, standard deviations, and correlation times. Design equations are given for the effluent mean and coefficient of variation for both concentration and mean flow rate. In addition, an approximation is suggested for the specification of the probability that the effluent concentration exceeds certain design values. For the case of a first-order reaction in the basin, it is shown that although the effluent mean is reduced, the coefficient of variation may not be reduced significantly in some instances. Design examples and validation of the formulas using actual influent records are included.