Ms Geraldine Tallon:

We go down the PPP route where the initial evaluation determines that it will be more effective over the full life cost. However, if the initial evaluation, based on the public sector benchmark, indicates that this will not be the case, we use traditional procurement. We have traditional procurement now by way of fixed price contract, rather than variable price contracts which used to be the position. We have fixed price contracting since 2007 and this provides a good basis for comparison. Every wastewater treatment plant is, in a sense, customised to its location. Many issues arise relating to the size of the collection system, the topography of the area, whether it is a pumped or gravity system, the type of treatment provided, the loading on the plant, the management of the loading into the plant, the form of sludge treatment or whether it is an inland or coastal plant. There is a wide range of factors involved and the technology is complex. Every assessment is done on a site specific basis, depending on the range of factors that applies in an individual location. There can be a significant variation in the cost and the whole-life costings depending on the particular factors that apply in any given location.