HS2, Colne Valley and the threat to London’s water supply

The chalk hills of the Chilterns act as a giant reservoir, with water slowing seeping down into streams in the Colne Valley and onwards into the Thames Valley to London. The crowded South East often has periods of being low on water and with the area around the Colne Valley supplying 22% of London’s water, the threat of water pollution is a major concern. There is an obvious danger to drilling down 70m near a landfill site in the Colne Valley, which has been declared a special site of pollution. Despite previous leaks from this landfill site leading to the contamination of a local river and the permanent closure of a pumping station, HS2 think it is worth risking London’s water supply.  Local people, such as Green Party campaigner Sarah Green, disagree strongly.

I asked two Parliamentary questions to raise the campaigners’ concerns. The answers confirm that the old landfill site is under the control of the Environment Agency, but they appear to be taking a hands off approach to regulation. It appears that the EA have not produced their own risk assessment but have asked HS2 to do it. Nor have the EA recognised the extent of the spread of contamination from the landfill site and their responsibility to stop the drilling from spreading that pollution further. Which gives me plenty of material for further questions.

Every examination of the detail of HS2 leads to further questions about the bigger picture. If things do go wrong and further investment in water treatment is needed, it will not be cheap. Closure of a second pumping station, at Blackford in Hillingdon, would increase the need to ‘import’ water from elsewhere in the UK. Those costs would be added onto the bill for HS2 but have not yet featured in the cost benefit analysis for the project.

As always, clean water is seen as a free resource. And it should be something we should be able to take for granted, like clean air, but neither the government, nor major companies like HS2, see keeping it clean as a key priority. There are almost certainly big problems, and big expenses, ahead if HS2 actually happens.