A new approach for water treatment

A quantity of up to 4000 m3/h of water is used at CERN for cooling purposes: experiments, magnets and radio frequency cavities are refrigerated by closed circuits filled with deionized water; other utilities, such as air-conditioning, use chilled/hot water, also in closed circuits. All these methods all employ a cold source, the primary supply of water, coming from the cooling towers. About 500 kCHF are spent every year on water treatment in order to keep the water within these networks in operational conditions. In the line of further rationalization of resources, the next generation of contracts with the water treatment industry will aim for improved performance and better monitoring of quality related parameters in this context. The author will provide a concise report based upon an examination of the state of the installations and of the philosophy followed up until now for water treatment. Furthermore, he/she will propose a new approach from both a technical and contractual point of view, in preparation for a call for tender which is foreseen to be issued during 1999. As the water tower circuits (primary water) are quantitatively dominating, the technical discussion will concentrate mainly on problems linked with these networks.