At a time when territorial authorities were primarily responsible for managing solid waste, Redvale was the first privately owned landfill in New Zealand. It was developed to serve the burgeoning population of Auckland, and was then easily the largest landfill in the country at 20 million m³. It was also the most modern landfill – ushering in to New Zealand a new era of highly engineered solid waste management facilities.
Right from the beginning, we worked with Waste Management International Inc.’s team of engineers to select the site and to progress it from concept designs through to consenting. Resource consents were granted in 1992 and we moved straight into detailed design and construction of the site access and facilities and the first stage of the landfill.
Over the years, we have partnered with the owner, Waste Management NZ, to develop a total of 17 landfill cells at Redvale. We have also undertaken a wide range of ancillary projects including the site drainage and stormwater treatment system consisting of six stormwater treatment ponds.
Redvale landfill is located in a geological formation that is ideally suited to waste disposal. The thick layers of very low permeability mudstone and limestone beneath the site make it very difficult for contaminants to leak out of the landfill.
The geology however is also highly challenging, and most projects at Redvale require significant input from our engineering geologists and geotechnical engineers. Key among these are the temporary slopes and sides of the landfill pit, some of which are up to 50m high. In addition, six large temporary and permanent stockpiles have been developed on and around the site.
The landfill includes a gas to energy plant, flares and a leachate evaporator developed largely by the owner. We have provided expert support to the air discharge consents required for this facility.
- Stormwater reticulation design
- Stormwater pond design
- Engineering geology
- Geotechnical engineering
- Slope stability
- Retaining wall design
- Contaminant transport modelling
- Air discharge assessment
- Solid waste engineering
- Leachate collection design
- Earthworks design
- Contract specification and preparation
- Bridge design
- Roading and pavement design
- Structural engineering
- CAD modelling
- Whole-of-life planning