The "City" installed a sewer system as part of overall infrastructure improvements for the CFD1 project. The sewer system included 3650 m (12,000 ft) of Vitrified Clay Pipe (VCP) 20 cm (8 in) dia. to 30 cm (12 in) diameter main lines at depths from 3 to 7.3 m (10 to 24 ft), and 89 VCP 10 cm (4 in) service laterals. Within months of installation 35% of the service laterals had leaks, breaks, and misalignments. The contract identified the site conditions, extent and details of the work required to be performed in conformance with the contract drawings and specifications, the required schedule of 147 days, and the contractor's responsibilities for ensuring total quality control for the project on materials, and workmanship. The city engaged a company other than the engineer of record to provide site supervision, inspection, and monitoring similar to those outlined in the specifications. In addition, the company that had earlier carried out the geotechnical investigation was retained by the site supervision firm to provide geotechnical inspection services during construction of the project as required by the specifications. The senior author was engaged by the City's Attorneys to review the design, specifications, and construction practices including inspection and monitoring, and a current condition assessment on this project as part of an engineering evaluation of the deep sewer system. The review also involved identifying deficiencies in design, installation, inspection and monitoring, and parties responsible for such deficiencies and any negligence. This paper documents the lessons learnt.
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