Five continuous microfiltration units (CMFUs) were installed at the Metropolitan Water District of Southern California's (Metropolitan's) Colorado River Aqueduct pumping plants. The first CMFU was brought on-line November 5, 1993, and the last in March 30, 1994. These five CMFUs have operated on a continuous basis, with very limited operator involvement. The CMFUs have also met all expectations regarding the quality of the treated water (i.e., turbidity and pathogen removal). Initially, the chemical cleaning process required a greater time commitment than originally anticipated. When the first two CMFUs were brought on-line and operated at the design flux rate, chemical cleaning was required every 2-3 weeks. The minimum run time between chemical cleans was ultimately extended to 1 month. This paper provides an overview of Metropolitan's experiences with the CMFUs, from pilot testing to full scale implementation. However, the emphasis of this paper is on the operational issues and requirements of the full scale CMFUs. Although this paper is a site-specific case study of Metropolitan's experiences and findings, these findings could also be applied to other installations.