Susan Yi is an environmental engineer for the Philadelphia Water Department in the planning and engineering division conducting a pilot scale research project to optimize water treatment control operations. She is currently conducting a study that explores the application of Magnetized Ion Exchange (MIEX) pretreatment on Philadelphia's source water and how MIEX can reduce chemical demand and reduce disinfection by-products, organics, and metals in the water better than conventional treatment practices. Susan also has experience with the Office of Watersheds in the modeling group, simulating sewer response to various storm events and evaluating flow monitoring data.