Hollow fiber Ultrafiltration / Microfiltration (UF/MF) membranes have historically been challenged to treat feed waters with even low concentrations of oil and grease. Piloting at the GRIP proof-pilot site in Pico Rivera, CA recently revealed Hollow Fiber UF membranes can treat municipal tertiary effluent with occasional spikes in oil and grease, even with a 2-stage UF system. This paper, if accepted, will specifically discuss the detailed operations of the 2-stage UF pilot system along with the 3-stage RO pilot system which was in operation from March to November 2017.