Marginal cost effectiveness analysis for agricultural nonpoint source water quality control

ABSTRACT:

Sediment in irrigation return flows significantly degrades water quality. Many studies in the past have used average cost efficiency to evaluate practices for water quality control. This study proposes and applies a technique for matginal analysis that considers change in cost per unit change in sediment reduction. This technique produces a cost efficiency frontier that evaluates practices for achieving alternative levels of sediment control. Inefficient practices are dominated by cost effective practices on the frontier and are purged from the hierarchy of cost effective practices for water quality control. In the study area, for most control levels, treatment practices that clean up runoff are more cost effective than preventive practices that control erosion.