If you have a sewer emergency or sewer related problem, please Call Us First, day or night at ( 650 ) 321-0384. Our reporting line is open 24/7. Thank you! Mission West Bay Sanitary District is dedicated to protecting the public health and the environment by providing cost effective sanitary sewer service. We are committed to providing our customers with wastewater disposal services utilizing the highest technical, environmental, and safety standards available ; to providing the very best customer service ; to ensuring the fiscal viability of our District by applying sound business principles and to ensuring the optimum operation of our infrastructure by employing professional maintenance and replacement practices. The District is situated in the southeasterly portion of Rancho de las Pulgas, in what is now San Mateo County. In 1851, Dennis J. Oliver and his brother-in-law, D.C. McGlyn, had acquired about 1, 700 acres of the rancho. Three years later, at a point just south of where Santa Cruz Avenue now enters El Camino Real, they erected a gate with an arch bearing the words Menlo Park, August 1854.