Patricia (Trish) Holden is a Professor in the Bren School of Environmental Science & Management, University of California, Santa Barbara and Director of the UCSB Natural Reserve System. Her training is in Civil & Environmental Engineering (CEE; B.S., University of Tennessee and M.S., Purdue University) and Soil Microbiology (Ph.D., U.C. Berkeley) with 8 years professional CEE experience. She leads a research group studying pathogens, pollutants, and microbial processes. Methods include conceptual modeling, field sampling and characterization, and laboratory experimentation. Research projects include: 1) synthetic microfiber, and micro- to nano-plastic, sources and environmental fates, 2) origins and fates of environmental pathogens, 3) the urban water environment (UWE): spatial relationships between urban infrastructure and subsurface contamination, 4) natural treatment systems for stormwater runoff, 5) distribution and function of subsurface soil bacteria, 6) microbial interactions with engineered nanomaterials, 7) tobacco and cannabis product pollutants, and cannabis cultivation chemicals. Holden is a Switzer Environmental Fellow.