Design capacity of rainfall runoff in a treatment scheme with sedimentation in an accumulation tank

Summary

An iterative calculation of volume-flow rate parameters of the treatment facilities for the 1st type surface runoff for the operating mode with runoff sedimentation in an accumulation tank is presented. The calculation is made using current long-term climatic data on the actual series of rains and average duration of periods between runoff-producing precipitation for a given area. It is shown that the capacity of the treatment facilities determined by the routine calculation does not provide for meeting the regulatory requirement for the treatment of the 70% average annual (average seasonal) amount of the runoff. The most economical option is storage type treatment facilities without runoff sedimentation in the accumulation tank. In this case, the regulatory requirement for the treatment of 70% average annual (average seasonal) amount of the runoff is achieved provided the capacity of the treatment facilities 4.3 times lower than in the scheme with sedimentation in the accumulation tank.

Key words

accumulating tank capacity , capacity of treatment facilities , annual series of daily precipitation layers and rainwater runoff , 1st type surface runoff , conditional period of processing the design rainfall runoff