- The North Waikato Regional Landfill (NWRL) is owned and operated by EnviroWaste and is the largest operating landfill in New Zealand. The NWRL was opened in 2005 and comprises of a fully engineered landfill with a footprint of 87 ha contained within a 360ha site.
- Leachate at NWRL is currently tankered off site and disposed of at into the Watercare wastewater network. Current discharge rates are 150 to 300m3/day at a cost of $22.00/m3 with a total cost of more than $1m/year. Operating costs were projected to exceed $2.5m by 2020.
- Several options were investigated into treatment. No local disposal options were available without significant pre-treatment. Options investigated were evaporation, reverse osmosis and local disposal.
- The most viable option chosen was treatment via Reverse Osmosis which gave an attractive removal of contaminants with a proven history of successfully being used at landfills throughout the world. New Logic Research from San Francisco were flown to New Zealand to conduct trials on the leachate. There process uses Vibratory Separation Enhanced Processing (VSEP) which helps mitigate colloidal fouling of RO membranes. The pilot test showed a 60-73% recovery of permeate.
- Construction of the plant commenced in November 2015 and full commissioning in June 2016.
Resource - Conference Papers