View all publications

1 Introduction

1.1 Background

It is the responsibility of the Ministry for the Environment to report to the Government and the wider community on the state of New Zealand’s environment, which includes the disposal of solid waste to landfill. To further this process, the Ministry has identified a core set of environmental indicators that will be regularly monitored and reported as part of an ongoing national state of the environment programme.1 The core indicator for solid waste has been identified as “trends in quantity and composition of solid waste to landfill”, which is to be measured in terms of the “quantity (by weight) and composition of solid waste to landfill by waste categories (eg, paper, plastic, glass, metal, organic, concrete, wood)”.2

The Ministry for the Environment is also party to The New Zealand Waste Strategy, and is responsible for monitoring progress towards the Strategy’s goals. Targets that are relevant to the monitoring of the composition of solid waste have been set in the Strategy for organic waste, garden waste, other organic waste streams, commercial organic waste, and construction and demolition waste. The complete text of the relevant targets from the Strategy is given in Appendix 1.

To assist with monitoring the core environmental indicators, in 2002 the Ministry instituted the Solid Waste Analysis Protocol (SWAP) Data Programme, which involved generating solid waste composition information at four indicator sites around New Zealand and periodically updating this data to establish longitudinal trends. In 2003/04 quarterly waste audits were undertaken over a two-year period at four sites, one rural and one urban, in both the North and South Islands. The four sites monitored for the baseline data were:

  • Green Island Landfill (Dunedin City Council), South Island

  • Silverstream Landfill (Hutt City Council), North Island

  • Matamata Transfer Station (Matamata−Piako District Council), North Island.

  • Kaikoura Landfill (Kaikoura District Council), South Island

To update the data from the 2003/04 audits, and to assist with monitoring the goals in The New Zealand Waste Strategy, in 2007 the Ministry tendered for four quarterly audits of the same sites to be undertaken during 2007/08. The auditing contract for the four sites was awarded to Waste Not Consulting Ltd.

1.2 Structure of report

Following this introduction, Section 2 describes the methodology used for gathering and analysing waste composition data for all of the Waste Data Programme audits. This includes a discussion and assessment of different types of auditing methods. Section 3 presents a summary of the results of the four surveys at each of the SWAP Baseline Programme sites.

The results of the four audits undertaken are shown in Sections G1–G7 (Green Island Landfill), S1–S7 (Silverstream Landfill), M1–M7 (Matamata Transfer Station) and K1–K7 (Kaikoura Landfill). The structure of the analysis in each section of the results is based on two waste streams. The results of the survey of general waste disposed of at the transfer station or disposal face, or both, are presented first. This is followed by the results for the overall waste stream, which are generated by combining the results of the surveys with an analysis of the weighbridge records for the survey period.

Each site specific section summarises the findings of the four audits and identifies trends in the types of waste and the composition of waste being disposed of over the course of the audit. There is also a discussion of the application of the results in terms of the objectives of the SWAP Data Programme.