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RECORD NUMBER: 25 OF 729

OLS Field Name OLS Field Data
Main Title Alum Control of Internal Phosphorus Loading in a Shallow Lake.
Author Welch, E. B. ; Michaud, J. P. ; Perkins, M. A. ;
CORP Author Washington Univ., Seattle. Dept. of Civil Engineering.;Corvallis Environmental Research Lab., OR.
Year Published 1982
Report Number EPA-R-804588; EPA-600/J-82-422;
Stock Number PB84-153683
Additional Subjects Phosphorus ; Lakes ; Water pollution control ; Aluminum sulfate ; Alums ; Cyanophyta ; Recovery ; Transparence ; Clarity ; Phytoplankton ; Chlorophylls ; Sampling ; Biomass ; Water quality ; Washington(State) ; Reprints ; Organic loading ; Trophic level
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Status
NTIS  PB84-153683 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 06/23/1988
Collation 11p
Abstract
Alum treatment of a shallow lake, with mean depth 2 m and area 137 ha, curtailed internal loading of P for at least one year. Mean summer total P and chl a decreased from 76 and 27 micrograms/l, respectively, in 1978 before treatment, to 29 and 14 micrograms/l, while mean summer Secchi transparency increased from 1.6 to 2.2 m and blue green algae were no longer dominant. Macrophyte biomass and distribution returned during the post-alum year, 1980-1981, to previous levels after a 1979 four-month lake level drawdown had reduced biomass by 84 percent. The improved transparency, resulting from the decrease in chl a following treatment, could encourage greater biomass of macrophytes in the deeper area of the lake. Recovery of macrophyte biomass to predrawdown levels may restore internal loading of P through enrichment of deep water sediments during winter dieback and decomposition.