The accumulation of residual coagulant flocs and microbial substances on the surface of ultrafiltration (UF) membranes are major contributors to membrane fouling that reduces process performance. Previous approaches to reduce fouling (e.g. addition of an oxidant or disinfectant) have been only partly successful in reducing the formation of a cake layer and material deposits within membrane pores. In this study the performance of an integrated granular media - UF membrane process has been evaluated in which a hollow-fibre UF module was embedded within a sand layer in order to prevent fouling material reaching the UF surface (forming a cake layer). The evaluation involved comparing two laboratory-scale UP systems, operated in parallel for 74 days, with one incorporating the sand layer (CSUF, coagulation-sand layer filtration-ultrafiltration), and the other without (CUF, coagulation-ultrafiltration), serving as a reference conventional process. The results showed that the incorporation of the sand layer successfully prevented the formation of any significant cake layer on the membrane surface and substantially reduced inner membrane fouling, which lead to a much reduced transmembrane pressure (TMP) increasing rate. The difference in performance was principally attributed to microbial growth and the release of extracellular polymeric substances ([PS) which was much greater in the conventional CUP system. Thus, in the CUP system, the deposition of coagulation flocs (consisting of precipitated nano-scale primary particles) and bacteria on, and within, the membrane produced substantial reversible and irreversible fouling. In contrast, the deposited material (flocs) in the sand layer of the CSUF system was easy to be washed away, resulting in fewer bacteria in the sand layer, and a much reduced production of biopolymer and other EPS, and their accumulation by the UP membrane. (C) 2015 Elsevier B.V. All rights reserved.