Development and demonstration of a free surface flow-dependent sampling technology

Statistical assessment of water quality data, obtained at the South Florida Water Management District (West Palm Beach, Florida) S-65E structure, illustrated significant differences and inconsistency in nutrient concentrations (Daas and Ebadian, 2003). The evaluation showed that currently used water sampling techniques are inadequate because of deficiencies in functionality and sensitivity to flow conditions at the structure. Moreover, the study indicated the need for a more precise sampling technology, which would consider variations in the velocity profile across the water column during the sampling process. Therefore, a new prototype sampling technology was designed and tested in a pilot open channel. The new sampler had the capability to collect discrete aliquot volumes of water samples that are proportional to the corresponding point velocity at each of these depths. The discrete aliquot volumes were blended to provide an integrated sample that captures the variations in the velocity profile.