2008. The pilot plant was operated for two years through to October 2010 and provided valuable information to further optimise the design of the main plant. The procurement process for the construction of the plant was: Expressions of interest (July 2008) Request for proposal to short-listed respondents (September 2008) Evaluation and negotiation Contract execution (February 2009). The preferred respondent was a consortium (AdelaideAqua D&C) consisting of McConnell Dowell, Abigroup and Acciona. A 20-year operations and maintenance contract was awarded to AdelaideAqua Pty Ltd, a consortium comprising Acciona and Trility. Completion of the initial 50 GL/year stage was initially targeted for the end of June 2012. Subsequently, with deteriorating drought in South Australia, the project was fast-tracked to compress the planning and procurement program and target early 'first water' (or 10% of plant output) up to 12 months earlier, followed by progressive completion of the remaining 50 GL per year plant. The first stage of the project began producing drinking water in October 2011, and the expanded plant began producing drinking water in July 2012. The plant was officially opened on 26 March 2013. Plant design The Adelaide Desalination Plant removes salt from, or desalinates, seawater using the process of reverse osmosis. This involves three main stages: Stage 1: Pre-treatment to remove particulate (non-dissolved) material from the seawater. Pre-treatment at the plant is achieved in three steps. Band screens remove coarse solids greater than 3mm from the water before it is pumped into the plant. Disc filters filter the water further, removing material larger than 0.1 mm (100 micron). Ultra-filtration membranes then remove material larger than 0.04 micron, including bacteria and most viruses. Stage 2: Reverse-osmosis to remove dissolved salts from the water. The water is pumped through a full two pass reverse osmosis system (i.e. all water passes through two separate reverse osmosis membranes) where dissolved salts are progressively removed. Approximately 48.5% of the feed water is converted to low salinity water, termed permeate, while the remainder is returned to the sea as saline concentrate. Stage 3: Post-treatment to prepare the water for distribution. The permeate from the reverse osmosis system is stabilised and then chlorinated and fluoridated ready for distribution. It is stored in 50 megalitre tanks onsite before it is transferred to the Happy Valley Water Treatment Plant through the transfer pump Station. Workplace safety The health and safety of all workers and stakeholders associated with the project