Quality Considerations for Water Supply Evaluations

In regions where the water quality of the sources can vary, the beneficial effects of the higher quality water should be considered. This is particularly true in the Southwestern United States where the mineral content of the water can vary among the various sources such as local ground water, local surface water, and imported water. This paper describes a procedure that was used in a water supply study in Ventura County, California. The study involved the evaluation of several sources of water having varying mineral contents. The procedure used considers the additional consumer costs for high mineral content water for both the domestic and industrial user. The procedure also develops the agricultural benefit costs for the lower water requirements and the higher crop yields associated with lower mineral content water. The total project cost of an alternative should be adjusted by the proper benefit cost accrued through the use of a high quality water.