§ Simon HughesTo ask the Secretary of State for Environment, Food and Rural Affairs what proportion of the population in their domestic premises in Greater London has access to(a) mains sewerage systems, (b) unadopted sewers, (c) sewers connected to a private treatment facility and (d) septic tanks. [168943]
§ Mr. MorleyDetailed information on the number of properties served by various types of sewerage system is not available. However, estimates do exist.
(a) I have been informed by Thames Water that the vast majority of properties in the Metropolitan London area are connected to the foul water sewerage system. I understand that virtually every property has the opportunity to connect to the public sewerage system under Section 106 of the Water Industry Act 1991.
(b) Nationally around 40 per cent. of properties connect to public sewers via unadopted sewers. (This is assuming 'unadopted sewers' mean all private sewers i.e. they are not adopted by the relevant sewerage undertaker). Separate data for Greater London are not available.
(c) Nationally around 10 per cent. of properties are estimated to be connected to completely private systems. This includes those connected to private treatment facilities, septic tanks and cesspools. Separate data for Greater London are not available.
(d) No data are available on the number of properties with a septic tank, as distinct from other forms of private sewage treatment, either nationally or for Greater London.