Jackson Lake: Response to Nutrient Reduction
Jackson Lake is a 4750 acre Georgia Power Co. impoundment of the Ocmulgee River located 40 miles southeast of Atlanta. The lake was formed in 1911 by the closure of Lloyd Shoals Dam and has served as an important recreational resource since that time. In the 1960's, Jackson Lake exhibited signs of rapidly accelerating eutrophication. Symptoms included fish kills, algal blooms, hypolimnetic anoxia and floating debris. Subsequent studies revealed the primary cause to be excessive input of nutrients, mainly from the South River and to a lesser extent from the Yellow River. The principal nutrient inducing algal growth was found to be phosphorus. By the mid 1970's construction projects were initiated to improve wastewater treatment in the South and Yellow River Basins. Major upgrades to facilities in both basins included phosphorus reduction. The City of Atlanta also initiated the Three Rivers Project which diverted treated wastewater from two facilities on the South River to the Chattahoochee River, and another major discharge was diverted to a land application system. In 1983, DeKalb County instituted advanced treatment with phosphorus reduction at the Snapfinger Water Pollution Control Plant, and in December 1984, the City of Atlanta began operation of the Three Rivers pipeline. Also, in early 1986, facilities to handle the "first flush" from three combined sewer overflows in the upper South River Basin were put into service.