DHML was contracted to Waste Management NZ Ltd between 1994 and 1998 for $9.3M to construct two earth dams, two major haul roads, and a major earth retaining structure to support a weak fill area to store overburden from the landfill site. The work progressed over 5 construction seasons.
Excavation and dumping totalled approximately 0.5M m3 of mudstone for a future landfill site, and construction of wall and floor liners of re-compacted and in-situ mudstone for waste cells to control leachate waters. Materials included very moisture sensitive mudstones overlain by high moisture content clays.
Field compaction and laboratory testing was undertaken by the Client, however internal field-testing allowed DHL to continue with earthworks while the Client’s test results were being processed.
A close spirit of co-operation developed with the Client, especially with regard to changing design. Significant organisation and management of on-site traffic was required, involving Waste Management, Redvale Lime and DHL vehicles. Considerable time was spent maintaining the stringent environmental considerations.
The client, Waste Management Ltd, in recognising the company’s performance, on completion of the project commended the company’s professionalism and responsible approach throughout the contract.