POOR QUALITY construction, renewal and maintenance of the UK's sewer network is causing leaks which are polluting the nation's groundwater.
According to a report to be published later this year by the Robens Centre for Public and Environmental Health, the contamination represents a serious threat to public health and, it says, will need huge investment before the water can be used for drinking.
The report, Distribution of microbiological contaminants in Triassic Sandstone water aquifers, states that sewer leakage 'has serious implications for the potential utilisation of urban groundwater resources and for rural boreholes in the vicinity of sewage sources'.
Sewer leaks are frequently the result of poor supervision, design or materials during repair works. If a smooth internal finish is not achieved, rats can attack weak spots and cause leaks more easily.
Contaminants from these leaks were not previously thought to reach aquifers, as it was assumed they were filtered by rocks above.
But the author of the report, the University of Surrey's Mike Barrett, explained that the dominant contaminant discovered during research in Birmingham and Nottingham was not from past industrial use, as originally thought, but from sewers. The problem, he claimed, is far worse than originally feared, with sewer contamination penetrating up to 90m into the regions' sandstone aquifer.
Funding cuts for sewer replacements and repairs are set to increase the problem, according to Stephen Battersby, also of the University of Surrey. Speaking this weekend at a European Federation of the Vitrified Clay Pipe Industry conference in Barcelona he explained: 'New assets will often have a shorter life than those which they are replacing due to their poor quality'.
He added that under investment had left the rate of renewal so low that water companies should concentrate on quality rather than quantity of replacements.