The expert panel (NCE 25 May) gives the Water Infrastructure a B Grade and indicates an improving situation.
Certainly, very substantial investment continues to be made by the industry but, in the case of the sewerage service, this is directed at improvements to the water environment. When this investment is completed after five years or so, the great majority of the ageing asset base of sewers will have been left untouched.
The funding allocated to capital maintenance of sewers is very low in comparison with their replacement cost and analysis of the figures published by Ofwat indicates sewer asset lives are from hundreds of years to - in some cases - thousands of years at present rates of replacement.
Little is known of the potential working life of sewers and, accepting that the funding required for wholesale replacement of sewers is neither available nor probably justified, vigilance must be maintained by the companies through adequate levels of inspection to ensure that the improvements in performance currently being achieved are not negated by unforeseen deterioration of the supporting infrastructure.
Brian Wilkinson, chairman, National Sewerage Association, 15 Mount Gardens, Alwoodley, Leeds LS17 7QN