Current research topics are: vertical subsurface barriers for the remediation of hazardous waste sites; transformation of slurry trench cutoff wall materials from the passive hydraulic barrier materials into active treatment materials while maintaining their passive hydraulic barrier characteristics; flow in compounds section open channels with mixed flow at a free overfall; interaction of main channel and flood flows in unsteady flow; design of steel structures using advanced methods of analysis; appropriateness of existing numerical models for nonlinear transport processes in environmental systems; pedestrian safety; guardrails and median barrier crash worthiness; tests of open web steel joist; full-scale tests of metal-plated timber trusses; rotational stiffness of truss heel joints; stiffness coefficients of metal plated connected truss joints with varying direction of loading between grain angles and metal plate axis; in-situ nondestructive testing of timber structural members; vibration serviceability; the diffusion of having engineers and architects design for construction safety; biodegradation of municipal solid waste in engineered reactors; coagulation, flocculation and sedimentation in aqueous systems; mitigation of odor potential at wastewater and solid waste treatment facilities; bioremediation of contaminated ground water; adsorption of heavy metals by microorganisms; characterization of pollution from agricultural sources; biological conversion of waste materials to useful forms of energy, such as methane and hydrogen, lifecycle analysis of engineered environmental systems.