Alexandria Boehm's primary research areas are coastal water quality and sanitation. The work on coastal water quality is focused on understanding the sources, transformation, transport, and ecology of biocolloids - specifically fecal indicator organisms, pathogens, DNA markers for key marine species, and phytoplankton, as well as sources and fate of nitrogen and phosphorus. Recent work has also focused on engineered natural systems at the coast to remove contaminants from stormwater. This knowledge is crucial to directing new policies, and management and engineering practices that protect human and ecosystem health along the coastal margin. The work on sanitation aims to develop microbial risk assessment models to gain a better understanding of how pathogens are transmitted to humans through their contact with water, feces, and contaminated surfaces. Research is focused on key problems in developed and developing countries. The goal is to design and test effective interventions and technologies for reducing the burden of infectious disease.