Verification of a depth-integrated sample arm as a means to reduce solids stratification bias in urban stormwater sampling.

A new water sample collection system was developed to improve representation of solids entrained in urban stormwater by integrating water-quality samples from the entire water column, rather than a single, fixed point. The depth-integrated sample arm (DISA) was better able to characterize suspended-sediment concentration and particle size distribution compared to fixed-point methods when tested in a controlled laboratory environment. Median suspended-sediment concentrations overestimated the actual concentration by 49 and 7% when sampling the water column at 3- and 4-points spaced vertically throughout the water column, respectively.

Water- and sediment-quality effects on Pimephales promelas spawning vary along an agriculture-to-urban land-use gradient.

Many streams in the U.S. are "impaired" due to anthropogenic influence.

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

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.