Susan Mulligan is a native of Southern California. She obtained her bachelor's degree in civil engineering from Stanford University and her master's degree in business administration from UCLA. She is a Registered Professional Engineer in the field of civil engineering and a Grade 5 Water Treatment Plant Operator.
Mrs. Mulligan started her career at the Pasadena Water and Power Department in 1984, working primarily in the fields of water quality and supply. She began work at Calleguas Municipal Water District in 1993 as Manager of Engineering, with responsibility for design and construction of capital projects. In 2010 she took on the position of General Manager with the goal of providing water reliability in an economically responsible manner.