§ Mr. FabricantTo ask the Secretary of State for the Environment, Transport and the Regions, pursuant to his answer of 16 June 1998,Official Report, column 131, if pipes and fittings which comply with the draft water industry specification for plastic sewage pipes will also be deemed acceptable for use in drainage systems which need to comply with the requirements of Part H of the Building Regulations. [47759]
§ Mr. RaynsfordThe requirements of the Building Regulations are cast in functional terms and do not prescribe specific solutions. The Approved Document to Part H of the Building Regulations provides guidance on how that requirement may be met. This guidance includes a list of materials which may be used for below-ground drainage pipes, and the relevant British Standards. However, products which conform to other standards may also be acceptable.
The pipes and fittings which are the subject of the draft water industry specification for plastic sewage pipes are innovative, and are not covered by the British Standards mentioned in the Approved Document to Part H of the Building Regulations. The draft water industry specification sets out the test criteria to enable the pipes to be judged fit for their intended purpose. These tests use similar performance criteria to those in the British Standards for more conventional pipes. Pipes and fittings which comply with the draft water industry specification for plastic sewage pipes should therefore be acceptable for use in drainage systems which need to comply with the requirements of Part H of the Building Regulations.
§ Mr. FabricantTo ask the Secretary of State for the Environment, Transport and the Regions, pursuant to his answer of 16 June 1998,Official Report, column 131, if the draft water industry specification for plastic sewage pipes will be expected to comply with the requirements of Part H of the Building Regulations. [47760]
§ Mr. RaynsfordThe draft water industry specification for plastic sewage pipes refers to pipes for use in sewers, and sets out the test criteria to enable pipes to be judged fit for their intended purpose. The requirements of Part H of the Building Regulations indicate the performance standards required for buildings with regard to foul water drainage, cesspools, septic tanks and settlement tanks, rainwater drainage and solid waste storage. The section relevant to sewers is H1, which states any system which conveys foul water shall be adequate.
However, the criteria which are used to demonstrate that a foul water drain is adequate and meets Requirement H1 are similar to those of the sewerage undertakers who specify the requirements for sewers. As a result, plastic sewage pipes which meet the draft water industry specification can normally be expected to comply with the requirements of Part H of the Building Regulations.
§ Mr. FabricantTo ask the Secretary of State for the Environment, Transport and the Regions, pursuant to his answer of 16 June 1998,Official Report, column 131, what are his reasons for accepting different specifications and requirements for pipes used in the construction of gravity sewers from pipes used in household drainage, with particular reference to water jetting resistance ranging from 1,900 to 5,000 pounds per square inch. [47761]
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§ Mr. RaynsfordThe Code of Practice for Sewer Jetting provides guidance on good practice when using high pressure water jetting equipment for unblocking and cleaning drains and sewers. It says that house drains should not be jetted at pressures exceeding 1,900 pounds per square inch. 5,000 pounds per square inch is the maximum pressure at which this guidance indicates sewers may be jetted, and this pressure applies to pipes in good structural condition laid in materials such as clay or concrete.
This document was prepared by the water industry, and the specifications within it are thus not formally endorsed by the Secretary of State.
§ Mr. FabricantTo ask the Secretary of State for the Environment, Transport and the Regions, pursuant to his answer of 16 June 1998,Official Report, column 131, what plans he has to ensure that all plastic drainage and sewage pipes withstand cleaning by high pressure water jetting. [47762]
§ Mr. RaynsfordA Code of Practice for Sewer Jetting has been produced by the water industry. In addition, the draft Water Industry Standard for plastic sewer pipes includes a test for resistance to jetting. Given that the industry is already regulating itself in this way, it is not considered that there is any need for the Government to intervene.
§ Mr. FabricantTo ask the Secretary of State for the Environment, Transport and the Regions, pursuant to his answer of 16 June 1998,Official Report, column 131, for what reasons pipes which comply with the draft water industry specification for plastic sewers may have a water jetting resistance of 1,900 pounds per square inch; what account he took of (a) the maximum recommended pressures set out in the Code of Practice in determining this level and (b) the requirement of Part H of the Building Regulations to minimise the risk of blockage and leakage. [47763]
§ Mr. RaynsfordThe draft Water Industry Specification for plastic sewer pipes gives 1,900 pounds per square inch as the maximum pressure for jetting sewers or drains where the composition or condition is unknown. However, this Specification was not prepared by my Department but was drawn up under the direction of the UK Water Industry Engineering and Operations Committee.