Abstract |
The report investigates the effectiveness of using natural meadowlands and wetlands to trap nutrients and sediments on land from surface and storm water runoff before they reach Lake Tahoe. Seven systems consisting of four streams and three drainage areas were studied. The study systems can be divided into those which remained channelized and those which spread as sheet flow across meadowlands. In the channelized systems, phosphorus, nitrogen, suspended sediments, and organic carbon concentrations usually remained unchanged or increased from the inlet to the outlet of the meadow. The sheet flow systems exhibited reductions up to 93% of total P, 71% of NH3(-)N, 96% of NO2(-)NO3(-)N, 82% of Kjeldahl-N, 94% of turbidity, 75% of TOC, 91% of POC, 91% of total residue, and 97% of non-filtrable residue. The effectiveness of nutrient removal in the functional systems approached that of conventional tertiary treatment. |