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NUTRIENT DIVERSION: RESULTING LAKE TROPHIC STATE AND PHOSPHORUS DYNAMICS
Citation:
Welch, E. NUTRIENT DIVERSION: RESULTING LAKE TROPHIC STATE AND PHOSPHORUS DYNAMICS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/3-77/003 (NTIS PB262645), 1977.
Description:
Lake Sammamish, Washington, was studied during 1970-75 to determine its response to wastewater diversion in 1968. The results were compared with a pre-diversion study in 1964-65. Diversion reduced the phosphorus loading by about one-third (from 1.02 to 0.67 g P/sq m. yr and about 119 to 68 micro g/l in the inflow). Winter total phosphorus remained constant and no trend was shown in chlorophyll a in spring-summer. Water transparency remained the same. Paleolimnological evidence suggests that the lake has been near its present mesotrophic state for about 100 years. This stability is thought to be due to the constancy of the water phosphorus concentration which is in turn controlled by the anaerobic-aerobic release and sedimentation of iron and its complexes.