Abstract: In this paper a new type interceptor sewer system is introduced and a model is establishedto solve the problem of optimal controlby analysing the facts on the interceptor sewer system and a Fortran program is produced for this model.This paper shows that the optimal control states can be determined by working out the optimalflow rates by means of the linear programming.A simple sewer system is conside red in order to examine the model as well as the program and the result is verysensible with interception points and the concentration weight coefficients overtime.The results farther highlight some practical applications for the existing interceptor sewer systems or the systems under design.