In order to produce a drainage area plan the manholes and sewers in the contributing catchments Manhole Surveying and Sewer Surveying needed to be carried out. USA Ltd. carried out 3,800 Manhole Surveys, cleaned 45km of sewer and CCTV surveying of 122 km of sewer as part of this contract. USA Ltd. also collated all information to produce a complete drainage network for all sewers feeding into the 9C Sewer.
The refurbishing of the River Liffey Siphons required a detailed survey of each of these structures to be undertaken. The survey of the 20 structures was undertaken by USA Ltd. Detailed drawings of the Siphons were produced.