Water quality improvement programming problems

Recent years have seen a marked increase in the rate of investment in facilities for water quality control and a concurrent recognition of the need to program water resource use on a regional basis. This paper outlines the nature of regional water quality systems and presents programming models for several water quality improvement problems. A linear programming formulation of a static improvement in quality is contrasted with a traditional policy for programming improvements; the traditional policy results in a mixed integer problem. The maximization of the ratio of benefits to costs of an improvement program is transformed to a linear programming problem. A stochastic natural environment leads to other programming models. A discussion of the application of least‐cost models terminates the paper.