Lateral drain survey

A lateral drain survey is a CCTV inspection of the section of drainage that runs from the property boundary to the connection with the public sewer, classed as a lateral drain under the Water Industry Act 1991. Since the 2011 private sewer transfer, most lateral drains in Greater London became the responsibility of Thames Water, but homeowners often still need a clear inspection to understand condition and resolve disputes. Engineers carry out the survey to BS EN 13508-2, grading defects against the WRc Manual of Sewer Condition Classification, and use sondes to confirm the exact boundary position. The output supports discussions with Thames Water about repair responsibility under Sewers for Adoption and informs any remedial works under BS EN ISO 11296, including cured-in-place lining and patch repair, carried out by qualified engineers.