Hydraulic size, as the main characteristic in calculating sump

A problem of sewage pollution is described in the article. At the moment, there are many ways to purify water. The most rational of them - upholding waste water in various reservoirs. To select the optimum sump need to calculate it for efficiency.The main parameter of calculation – is hydraulic size. The paper present methods for calculating sedimentation tanks and methods for determining the hydraulic size.