Three existing landfills for wastes from Carter Holt Harvey Pulp & Paper, Tasman have or are reaching the end of their lives. These landfills receive primary solids (boiler fly-ash, wood fibre and lime mud – dewatered to 25-30%), secondary solids (slurry of dewatered dredgings from wastewater treatment plant ponds) and dregs (sand, gravel and calcium compounds) are all typical of wastes for pulp and paper plants. New landfill capacity was required for these waste streams starting in 2013.
An innovative design was conceptualised and underwent detailed design with the construction of stage 1 of the facility during 2011-2012 earthworks season. At the heart of this innovative design is the concept of retaining one type of waste by using another. In this case using the primary solids to retain the secondary solids utilising tailings dam design principles. This paper looks at the Environmental impact and Risk considerations which were considered in the design and provides an assessment of the operation of the after a year of operation. Design aspects, the current waste streams, the operational aspects and learnings are presented. The innovative design has been accepted by the authorities who have issued resource consents for construction and operation of a new landfill facility which is known as the North Valley Landfill (NVL).