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The three primary goals of this project were to establish the ambient background of water quality in the Lake Boeuf basin in southeast Louisiana; establish land use patterns in the basin and the relation to water quality; and develop a preliminary plan to improve water quality through the use of best management practices and wetland assimilation. Urban and agricultural acreage borders the basin and runoff from these lands forces loadings of nutrients into the adjacent canals where they become channelized and ultimately exit the Boeuf Basin into Lac des Allemandes. From September 2007 until February 2008, water sampling occurred monthly at twelve discrete locations throughout the study area. These samples were tested for NOx, PO4, Si, NH4, salinity, TSS, TN, and TP. Results of this data showed concentrations in the basin were not extraordinarily high. Sites located nearer to sugarcane acreages showed higher nutrient concentrations as compared to other sampling sites. Field data was compared to an existing dataset compiled by the Louisiana Department of Environmental Quality for use in establishing total maximum daily loads for the basin. Statistical analysis revealed significant decreases of PO4 and salinity concentrations from years 2000 through 2008. A yearly nutrient load estimate for the basin was established for NOx, NH4, TKN, TN, and TP. Using cited nutrient removal curves, it was determined that the available wetland acreage in Boeuf Basin could assimilate these loads achieving nearly 100% removal. Reductions in nutrient loads can be achieved by implementing best management practices in the adjacent agriculture. Other solutions include reducing direct flow from sugarcane field drainage ditches and diversion of this drainage through the wetlands allowing for assimilation. |
