Significance of eutrophication in water supply reservoirs

Key relationships between eutrophication of surface water supplies and the costs and quality of finished water are reviewed, with an emphasis on problems relating to organics. Data from lakes and reservoirs in the United States indicate a positive correlation between total phosphorus and total organic carbon measurements. In view of this correlation and results of controlled laboratory studies reported in the literature, nutrient enrichment is a significant factor contributing to organohalide problems in surface water supplies. Watershed management for control or reduction of phosphorus export is suggested as a potentially significant and cost‐effective means of dealing with organics‐related problems. Regionally calibrated empirical models can be used in conjunction with appropriate reservoir and watershed monitoring data to assess the extent, significance, and controllability of water quality problems related to phosphorus export and eutrophication.