A hybrid desalination system of 6300m3/day capacity has been envisaged, comprising 4500 m3/day Multi-Stage Flash (MSF) and 1800 m3/day Seawater Reverse Osmosis (SWRO) plants, and sharing basic utilities with Madras Atomic Power Station. The SWRO plant has been commissioned and has been operating for more than two years. The MSF plant is under construction. The construction of the MSF plant has thrown up a number of challenges, particularly as it is being retrofitted to the existing power plant. The steam supply system and the intake system for seawater required a unique approach both in design and erection. With notable variation in raw water quality, the operation of the SWRO plant has provided valuable insight into the performance of the pre-treatment system and of the membrane. Copyright © 2006 Inderscience Enterprises Ltd.