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Development of a depth-integrated sample arm to reduce solids stratification bias in stormwater sampling

January 1, 2011

A new depth-integrated sample arm (DISA) was developed to improve the representation of solids in stormwater, both organic and inorganic, by collecting a water quality sample from multiple points in the water column. Data from this study demonstrate the idea of vertical stratification of solids in storm sewer runoff. Concentrations of suspended sediment in runoff were statistically greater using a fixed rather than multipoint collection system. Median suspended sediment concentrations measured at the fixed location (near the pipe invert) were approximately double those collected using the DISA. In general, concentrations and size distributions of suspended sediment decreased with increasing vertical distance from the storm sewer invert. Coarser particles tended to dominate the distribution of solids near the storm sewer invert as discharge increased. In contrast to concentration and particle size, organic material, to some extent, was distributed homogenously throughout the water column, likely the result of its low specific density, which allows for thorough mixing in less turbulent water. ?? 2010 Publishing Technology.

Citation Information

Publication Year 2011
Title Development of a depth-integrated sample arm to reduce solids stratification bias in stormwater sampling
DOI 10.2175/106143010X12851009156006
Authors W.R. Selbig, R.T. Bannerman
Publication Type Article
Publication Subtype Journal Article
Series Title Water Environment Research
Series Number
Index ID 70033939
Record Source USGS Publications Warehouse
USGS Organization