[PDF] Eutrophication Of Lake Tahoe Emphasizing Water Quality eBook

Author : Percy Harold McGauhey
Publisher :
Page : 176 pages
File Size : 27,94 MB
Release : 1972
Category : Eutrophication
ISBN :

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A survey was made of nutrient and other chemical constituents of surface waters from developed and undeveloped land areas, sewage effluents, seepage from septic tank percolation system and refuse fills, drainage from swamps, precipitation, and Lake Tahoe water. Algal growth stimulating potential of the samples were bioassayed with Selenastrum gracile as a test organism. Algal response to nutrients was measured by maximum growth rate and maximum cell count in a 5-day growth period. Ponds simulating the shallow portions of the lake were used for continuous flow assay of the biomass of indigenous lake organisms produced by sewage effluent. Flask assays and chemical analyses were made over two years on three major creeks. Twenty-eight other creeks and precipitations were monitored by chemical analysis. Evaluating the eutrophication potential, Lake Tahoe is nitrogen sensitive and responds to it in proportion to its concentration.

Author : Percy Harold McGauhey
Publisher :
Page : 132 pages
File Size : 28,6 MB
Release : 1971
Category : Eutrophication
ISBN :

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The water impounded at Indian Creek Reservoir near Lake Tahoe, California is approximately one-third surface runoff and direct precipitation and two-thirds reclaimed water exported from South Tahoe Public Utility District Plant. Discussed are the results of tests which determined the temporal changes and relationships between water quality characteristics of Indian Creek Reservoir and those of the reclaimed water. Initially the reservoir would not support fish life, but as the reservoir matured, ammonia levels declined to less than 4 mg/l and by 1970 it was an excellent trout fishery. Approximately 70% of the ammonia nitrogen was lost to the atmosphere by nitrification-denitrification. Good biological productivity indicated access to other phosphorus sources, probably runoff. Relative to conductivity and chemical components the water is of good irrigation quality. Various parameters showed that the reservoir responds to more complex factors than those measurable in the reclaimed waste water, raising the question of the effectiveness of tertiary treatment for recreational impoundments.