AWWA ACE56328

Utility managers at drinking water treatment plants faced with deteriorating raw water quality must allocate resources between increased treatment at the plant and promotion of best management practices (BMPs) in the watershed. This paper describes a methodology for evaluating the impact of point and nonpoint source pollution on water treatment costs, evaluating the potential of agricultural and urban BMPs to mitigate these impacts, and comparing the efficacy and cost of BMPs in the watershed with increased treatment at the water treatment plant (WTP). A screening-level watershed model is used to quantify changes in annual suspended solids and organic carbon loads exported under varying land use and BMP implementation scenarios, and a dynamic water treatment plant model is used to quantify the impact of associated changes in daily raw water quality profiles on water treatment plant operations and costs. Data on the ratio of catchment size to WTP size is used to determine the fraction of utilities that may benefit from BMP promotion. Includes 7 references, tables, figure.