Mr. Samstag has specialized in analysis of sedimentation problems for both primary and secondary sedimentation tanks. He worked with early pioneer Robert C. Crosby and adopted Crosby’s techniques for field test of sedimentation tanks. He has managed or led field tests at nearly two dozen sites including long column settling rate tests, solids profiles, residence time distribution, flow pattern distribution, and velocity profiling using drogues and acoustic Doppler anemometers. In more recent work he has applied the techniques that he has developed in analysis of sedimentation to mixing in activated sludge tanks and digesters. His work in developing techniques for coupling of solids gradients into mixing analysis has been an innovative area in the field. See project experience listed under the item CFD Modeling and Process Testing.