---

Dept for Environment Food and Rural Affairs

Answer

Mr. Grieve: To ask the Secretary of State for Environment, Food and Rural Affairs what steps the Government are taking to avoid a repetition of the flooding of the River Thames with raw sewage in August; and if she will make a statement. [199155] Mr. Morley: The sewage collection system serving London is comprised largely of combined systems which collect and transport for treatment both domestic and industrial waste water, and rainwater run-off. As sewers and sewage treatment works have a maximum capacity, it is a design feature of combined systems to have overflows which discharge in some wet weather conditions to prevent sewers from flooding, and sewage treatment works from being overloaded. Therefore, although we hope the environmental effects of the sewage discharge in early August aren't repeated, the overflows will continue to operate during some wet weather conditions. As agreed in the last Periodic Review of water company price limits for 2000-05, Thames Water, the Environment Agency, Defra and the Office of Water Services (Ofwat) have been involved in a Strategic Study of the environmental impact of intermittent storm sewage discharges to the Thames Tideway. The remit of the study was to identify objectives for improvement, and to propose potential solutions, having regard to costs and benefits. As a result of the study, the Final Guidance by the Secretary of State to the Director-General of OfWat, published on 4 October 2004, and the draft price limits published by Ofwat on 5 August 2004, include provision for further measures to address sewage discharges to the Thames Tideway. In the medium term this will result in improvements to the capacity and quality of treated effluent from three sewage treatment works (Beckton, Crossness, and Mogden) which discharge to the Thames Tideway. These improvements are also to include reducing the frequency of intermittent discharges from the storm water storage tanks at Mogden, which made a significant contribution to the pollution in August. In addition a scheme to improve the treated effluent at Riverside sewage treatment works, is identified to improve water quality in the river and protect fish. Also, as set out in the Final Guidance, we have asked Thames Water and the Environment Agency to undertake further work on a long-term solution proposed by the Strategic Study group, and on other smaller-scalemeasures that could bring earlier improvements on intermittent discharges.

Secondary information

Type

Written question

Reference

199155; 426 c2030-1W;426 c2036-7W

Session

2003-04

Subjects

Flood control Floods Sewage Waste disposal Water treatment River Thames

Link

View this Written question on www.publications.parliament.uk