Water Industry (Financial Assistance) Bill

In London, there is a real need for improvement to the sewerage system. The present network of major sewers was designed for a 19th century city. London's population is now 7.6 million, but it is projected to rise to 8.3 million by 2021 and to 8.8 million by 2031. It will then have doubled since the major sewers were built. That the system has managed so well for so long is remarkable, and a tribute to Bazalgette and the others who designed and built it. It is, however, clearly inadequate, and has been so for some time. The present system consists of combined sewers, which convey foul sewage and rainwater run-off to the sewage treatment works before they are discharged. When the combined sewers reach capacity, the combined sewer overflows—CSOs—are designed to discharge excess untreated waste water into the River Thames. This avoids overflows and back-ups through manholes and into individual properties, but it means that as soon as the hydraulic capacity of the sewage treatment works is exceeded, sewage is pumped directly into the Thames. In fact, some parts of London, including my constituency, also have a problem with sewage back-up, and the Counters Creek relief scheme that Thames Water is seeking to implement will bring an end to that appalling problem, which has affected thousands of my constituents over the past few years. It happened three times in four years during the latter part of the last decade. I welcome the implementation of the Counters Creek relief scheme—a major scheme across west London—but the result will be even more sewage going into the Thames. The river will continue to bear the brunt. Discharges can occur following as little as 2 mm of rain; they happen approximately 60 times a year. The Thames is tidal between Hammersmith and Beckton, and when CSOs discharge, the resulting sewage and litter flows up and down the river with the tide. In winter, it takes about a month for non-biodegradable waste to get from the head of the estuary at Teddington to the sea. In summer, when water levels are lower, it can take up to three months. It is in summer that we get the worst response and the worst smells. In future, sewage might flow into the Thames even on dry days unless the situation is managed. In any typical year, 39 million cubic metres of untreated waste water—a mixture of sewage and rainwater—are discharged. The frequency and volume of untreated waste water entering the tidal reaches of the Thames have increased, and will only increase further. This level of waste entering the environment is not tolerated anywhere else in the UK, and it should not be flowing into the main river of our capital city. Something clearly needs to be done. The discharges affect the river in several ways. First, polluted water increases health risks to recreational users of the Thames, whose numbers I am pleased to say are increasing year on year. Secondly, the aesthetic impact of CSO discharges is offensive. Materials such as faeces, toilet paper, wipes, sanitary products and other ““flushable”” items, including hypodermic needles, regularly end up in the Thames at Hammersmith. All of this causes slicks of pollution to float on the river before being washed up on the foreshore. Thirdly, sewage discharges harm the ecology of the river by reducing dissolved oxygen levels in the water. In extreme events, this can result in the death of fish and other wildlife, often in large numbers. There are therefore strong environmental, health and economic cases for the Thames tunnel. The Thames tunnel will work with the existing system of sewers, with improved sewage treatment works and with the Lee tunnel to reduce the frequency of CSO discharges. This Government and the previous one have conducted serious studies of the issues behind the tunnel. Investigations have been carried out by the Department for Environment, Food and Rural Affairs and by independent bodies, resulting in the 2007 regulatory impact assessment, the Thames tunnel needs report, and DEFRA's 2011 strategic and economic case for the Thames tunnel. They all conclude that the tunnel is the most comprehensive solution available at the most proportionate cost. A number of alternatives have been suggested. The first is that we have a system to mitigate and reduce the dissolved oxygen levels in the Thames. This involves using the so-called Thames Bubbler oxygenation craft, as well as hydrogen peroxide dosing. This has helped with fish mortality in some places, but it is not sustainable; neither is it a complete solution and neither will it work in a tidal river.