View all publications

K6 Summary of Results: 2007/08

In this summary of the results from the four surveys undertaken at Kaikoura Landfill as part of the SWAP Data Programme, comparisons are presented for the:

  • compositions of the four activity sources that make up the general waste stream

  • tonnages of the four activity sources and the general waste stream

  • compositions of the general waste stream

  • tonnages of the waste streams that make up the overall waste stream

  • compositions of the overall waste stream.

Average compositions are provided for the four activity sources that make up the general waste stream, the general waste stream and the overall waste stream.

K6.1 Activity sources

K6.1.1 Construction and demolition waste

The primary composition of C&D waste from the four surveys is shown in Figure K6.1.

Figure K6.1: Composition of C&D waste, 2007/08

Primary category 17-23 September 21-27 November 21-27 February 29 May-4 June
Paper 3% 3% 0.6% 0.3%
Plastics 4% 6% 1.0% 8%
Putrescibles 3% 5% 0.7% 0.5%
Ferrous metals 4% 4% 0.8% 4%
Non-ferrous metals 0.8% 1.0% 0.4% 0.4%
Glass 3% 4% 0.2% 3%
Textiles 3% 3% 3% 17%
Nappies and sanitary 0.2% 1.2% 0.1% 0.0%
Rubble 46% 43% 38% 37%
Timber 33% 27% 54% 23%
Rubber 0.9% 0.8% 1.0% 5%
Potentially hazardous 0.5% 2% 0.4% 3%

In each of the four surveys, rubble and timber were the largest components of C&D waste. Rubble (such as concrete) was the largest component in three of the four surveys, and timber in the fourth. In only one instance did any other primary category comprise more than 10 per cent of the total: large quantities of carpet and underlay in the fourth survey resulted in textiles making up 16 per cent of the total.

K6.1.2 Industrial/commercial/institutional waste

The primary composition of ICI waste from the four surveys is shown in Figure K6.2.

Figure K6.2: Composition of ICI waste, 2007/08

Primary category 17-23 September 21-27 November 21-27 February 29 May-4 June
Paper 12% 11% 14% 10%
Plastics 16% 17% 14% 13%
Putrescibles 23% 25% 28% 25%
Ferrous metals 6% 5% 6% 6%
Non-ferrous metals 0.9% 0.8% 1.1% 0.9%
Glass 5% 7% 9% 12%
Textiles 12% 7% 5% 10%
Nappies and sanitary 9% 10% 11% 10%
Rubble 4% 5% 2% 4%
Timber 9% 8% 7% 8%
Rubber 2% 1.2% 1.3% 0.9%
Potentially hazardous 2% 2% 2% 2%

ICI waste was relatively heterogeneous, with no single material comprising over 30 per cent of the total in any of the surveys. In each survey putrescibles comprised the largest proportion and plastics the second largest. The composition is closely related to the relative size of the hospitality industry in Kaikoura and the active resource recovery practised at the landfill.

For most of the categories there is a reasonable degree of consistency in the proportion of materials present. The categories that vary the most tend to represent relatively small proportions of the total waste stream, such as textiles and rubble. The variation that does exist in these categories is, in most instances, the result of a small number of homogeneous waste loads.

K6.1.3 Landscaping and earthworks waste

The primary composition of landscaping and earthworks waste from the four surveys is shown in Figure K6.3.

Figure K6.3: Composition of landscaping and earthworks waste, 2007/08

Primary category 17-23 September 21-27 November 21-27 February 29 May-4 June
Paper 0.5% 2% 0.0% 0.0%
Plastics 0.5% 2% 3% 0.0%
Putrescibles 77% 62% 85% 12%
Ferrous metals 0.1% 0.1% 3% 0.0%
Non-ferrous metals 0.0% 0.0% 0.0% 0.0%
Glass 0.2% 0.0% 0.0% 0.0%
Textiles 0.1% 0.0% 0.0% 1.0%
Nappies and sanitary 0.3% 2% 0.0% 0.0%
Rubble 17% 24% 5% 78%
Timber 4% 10% 4% 8%
Rubber 0.0% 0.0% 0.0% 0.0%
Potentially hazardous 0.0% 0.0% 0.1% 0.0%

Results from the four surveys show that the composition of the landscaping and earthworks activity source is generally made up of three primary waste categories: putrescibles, rubble and timber. In three of the four audits green waste represented over 60 per cent of the total weight. In the fourth survey rubble constituted nearly 80 per cent of the total. There were, however, only two loads of landscaping and earthworks waste in the fourth survey. This indicates the effect a small number of vehicle loads can have on the composition of this activity source, given that during the course of each survey only between 1 and 5 per cent of the total number of loads received at the Kaikoura Landfill were classified as originating from a landscaping and earthworks activity source.

K6.1.4 Residential waste

The primary composition of residential waste from the four surveys is shown in Figure K6.4.

Figure K6.4: Composition of residential waste, 2007/08

Primary category 17-23 September 21-27 November 21-27 February 29 May-4 June
Paper 12% 12% 12% 12%
Plastics 14% 17% 14% 12%
Putrescibles 29% 28% 24% 22%
Ferrous metals 10% 5% 7% 7%
Non-ferrous metals 1.0% 0.8% 2% 0.8%
Glass 6% 5% 5% 7%
Textiles 8% 7% 10% 11%
Nappies and sanitary 8% 8% 9% 11%
Rubble 4% 4% 4% 3%
Timber 7% 10% 12% 11%
Rubber 0.6% 1.1% 1.0% 1.1%
Potentially hazardous 1.0% 0.9% 1.2% 2%

Residential waste is relatively heterogeneous, with no single category of material comprising more than 30 per cent of the total in any of the surveys. In all of the surveys putrescible material, primarily food waste in residential refuse bags, was the largest classification. Plastics was the second largest classification in all four surveys, and paper the third.

K6.2 General waste

General waste discharged at the Kaikoura Landfill is defined as waste generated from four different activity sources: C&D, ICI, landscaping and earthworks, and residential (as illustrated in Figure K1.1). Figure K6.5 presents the tonnage of waste from each activity source for each of the four surveys.

Figure K6.5: Tonnage of activity sources of general waste, 2007/08

Primary category 17-23 September 21-27 November 21-27 February 29 May-4 June
Construction and Demolition 2.6 1.9 1.3 1.6
Industrial/Commercial/ Institutional 3.9 11.4 11.7 6.6
Landscaping and Earthworks 0.8 0.4 2.3 0.5
Residential 4.2 4.9 5.2 3.4
Total General Waste 11.5 18.7 20.5 12.1

Figure K6.5 shows that, in each of the four surveys, the quantity of general waste was made up of roughly constant quantities of waste from three of these four activity sources, although there was some seasonal variation. Waste generated from C&D activity was lowest in the summer, when tourism is at its greatest. ICI waste, conversely, was greatest during the summer tourist season. Residential waste was relatively constant by comparison.

Figures K6.6 and K6.7 present the variation in the composition of the general waste stream through the four surveys conducted in 2007/08. Figure K6.6 shows the tonnage of each of the 12 primary categories disposed of during each of the survey periods; the mean tonnage for each material is also marked in the figure. Figure K6.7 shows the percentage composition of the general waste stream based on the 12 primary SWAP categories for each of the four surveys.

Figure K6.6: Tonnage of general waste, by primary categories, 2007/08

Primary category 17-23 September 21-27 November 21-27 February 29 May-4 June Mean
Paper 1 1.9 2.2 1 1.5
Plastics 1.3 2.9 2.5 1.4 2.0
Putrescibles 2.8 4.6 6.5 2.5 4.1
Ferrous metals 0.7 0.9 1.1 0.6 0.8
Non-ferrous metals 0.1 0.2 0.2 0.1 0.2
Glass 0.5 1.1 1.3 1.1 1.0
Textiles 0.9 1.2 1.2 1.3 1.2
Nappies and sanitary 0.7 1.6 1.7 1 1.3
Rubble 1.6 1.7 1 1.3 1.4
Timber 1.5 2 2.2 1.3 1.8
Rubber 0.1 0.2 0.2 0.2 0.2
Potentially hazardous 0.1 0.3 0.3 0.2 0.2

Figure K6.7: Primary composition of general waste, 2007/08

Primary category 17-23 September 21-27 November 21-27 February 29 May-4 June
Paper 9% 10% 11% 9%
Plastics 12% 15% 12% 12%
Putrescibles 25% 25% 32% 20%
Ferrous metals 7% 5% 5% 5%
Non-ferrous metals 0.8% 0.8% 1.1% 0.8%
Glass 5% 6% 7% 9%
Textiles 8% 6% 6% 10%
Nappies and sanitary 6% 9% 9% 9%
Rubble 14% 9% 5% 11%
Timber 13% 11% 11% 11%
Rubber 1.2% 1.1% 1.0% 1.4%
Potentially hazardous 1.2% 2% 1.3% 2%

The graphs show that putrescible material consistently made up the largest proportion of general waste in each survey. Some materials varied more in terms of tonnages than others. For example, plastics and putrescibles showed a greater variation in tonnages than textiles and timber which were more consistent through the year. This difference is related to the variation in the activity sources: as the quantity of residential waste is more consistent than other activity sources, materials associated with residential waste vary less through the surveys.

The average proportions of the 12 SWAP primary waste categories that make up general waste are presented in Figure K6.8. The average composition is calculated using results from the four visual surveys conducted in 2007/08 and is based on the tonnages of the different materials. These are the mean figures from Figure K6.6 expressed as percentages.

Figure K6.8: Average primary composition of general waste, 2007/08

Primary category % of total
Paper 10%
Plastics 13%
Putrescibles 26%
Ferrous metals 5%
Non-ferrous metals 1.0%
Glass 6%
Textiles 7%
Nappies and sanitary 8%
Rubble 9%
Timber 11%
Rubber 1.1%
Potentially hazardous 1.4%

Putrescible materials, on average, comprised the largest proportion (26 per cent) of the general waste stream. Much of this putrescible material was food waste in residential refuse bags. Plastics, paper and timber each made up between 10 and 13 per cent of the general waste.

K6.3 Overall waste

Table K6.1 and Figure K6.9 present the quantity of overall waste from the results of the four surveys.

Table K6.1: Overall waste, 2007/08

Waste types Tonnes/week
  September 2007 November 2007 February 2008 May 2008
General waste 11.5 18.7 20.5 12.1
Kerbside collections 2.3 3.8 4.2 2.5
Special waste 0.8 1.3 2.4 6
Total 14.6 23.7 27.1 20.5

Figure K6.9: Overall waste, 2007/08

The results show that the overall waste was consistently made up of approximately five times as much general waste as kerbside collections, and these proportions did not change significantly across the four audits. The quantity of glass being landfilled in bulk (the only special waste), as opposed to being stockpiled, increased with each audit.

Figures K6.10 and K6.11 show the variation in the composition of the overall waste stream through the four surveys conducted in 2007/ 08. Figure K6.10 shows the tonnage of each of the 12 primary categories disposed of during each of the survey periods; the mean percentage is also shown in the figure. Figure K6.11 shows the percentage of the overall waste stream for each of the 12 primary SWAP categories.

Figure K6.10: Tonnage of overall waste, by primary categories, 2007/08

Primary category 17-23 September 21-27 November 21-27 February 29 May-4 June Mean
Paper 1.3 2.5 2.8 1.4 2.0
Plastics 1.7 3.4 3.1 1.8 2.5
Putrescibles 3.9 6.4 8.5 3.7 5.6
Ferrous metals 0.8 1 1.2 0.7 0.9
Non-ferrous metals 0.1 0.2 0.2 0.1 0.2
Glass 1.5 2.7 4 7.2 3.9
Textiles 0.9 1.2 1.2 1.3 1.2
Nappies and sanitary 0.9 1.9 2.1 1.2 1.5
Rubble 1.6 1.7 1.1 1.4 1.5
Timber 1.5 2 2.3 1.3 1.8
Rubber 0.1 0.2 0.2 0.2 0.2
Potentially hazardous 0.2 0.4 0.3 0.2 0.3

Figure K6.11: Primary composition of overall waste, 2007/08

Primary category 17-23 September 21-27 November 21-27 February 29 May-4 June
Paper 9% 11% 10% 7%
Plastics 11% 14% 11% 9%
Putrescibles 27% 27% 32% 18%
Ferrous metals 6% 4% 4% 3%
Non-ferrous metals 0.7% 0.7% 0.9% 0.6%
Glass 10% 11% 15% 35%
Textiles 6% 5% 5% 6%
Nappies and sanitary 6% 8% 8% 6%
Rubble 11% 7% 4% 7%
Timber 10% 9% 8% 7%
Rubber 0.9% 0.9% 0.8% 0.8%
Potentially hazardous 1.0% 2% 1.1% 1.0%

These graphs indicate that although putrescibles and plastics are the largest two categories in the first two audits, in the second two audits the quantity of glass being landfilled increases and glass is the largest category in the final audit. The proportions of paper, plastics, rubble and timber are similar in all of the audits.

The average primary composition of the overall waste stream is presented in Figure K6.12. The average composition for the four surveys has been calculated by averaging the tonnages from each survey. These averages are shown as the mean in Figure K6.10.

Figure K6.12: Average primary composition of overall waste, 2007/08

Primary category % of total
Paper 9%
Plastics 12%
Putrescibles 26%
Ferrous metals 4%
Non-ferrous metals 0.7%
Glass 18%
Textiles 5%
Nappies and sanitary 7%
Rubble 7%
Timber 8%
Rubber 0.8%
Potentially hazardous 1.3%

The putrescible waste category is the largest component of the overall waste stream (26 per cent), with glass representing an average of 18 per cent of the total. These categories are followed by plastics, paper, timber, nappies and sanitary, and rubble (all between 7 and 13 per cent).