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K5 Results: 29 May–4 June

K5.1 General waste

K5.1.1 Primary composition of general waste

The primary composition of the general waste is presented in Table K5.1 and Figure K5.1. The secondary composition, which includes all 22 categories, is given in Appendix K14.

Table K5.1: Primary composition of general waste, 29 May–4 June 2008

Primary category % of total
(±95% confidence level)
Tonnes/week
Paper 8.6 (±2.0) 1.0
Plastics 11.8 (±2.2) 1.4
Putrescibles 20.4 (±5.8) 2.5
Ferrous metals 5.3 (±1.3) 0.6
Non-ferrous metals 0.8 (±0.3) 0.1
Glass 9.2 (±3.8) 1.1
Textiles 10.4 (±5.2) 1.3
Nappies and sanitary 8.5 (±1.9) 1.0
Rubble 11.0 (±7.4) 1.3
Timber 10.9 (±3.6) 1.3
Rubber 1.4 (±0.8) 0.2
Potentially hazardous 1.6 (±0.4) 0.2
Total 100   12.1

Figure K5.1: Primary composition of general waste, 29 May–4 June 2008

Putrescible material was the largest single component of the general waste, comprising 20 per cent of the total. Paper, plastic, textiles, rubble and timber all comprised similar proportions of the general waste, with between 8 and 12 per cent.

K5.1.2 General waste, by activity source

The general waste being disposed of at Kaikoura Landfill comprises all waste other than kerbside collections and loads of glass collected by Innovative Waste Kaikoura and disposed of to landfill. During the survey period data was gathered on 245 loads of general waste. This included waste from C&D, ICI, landscaping and earthworks, and residential activity. As each load of general waste was disposed of, it was assessed as to which of these activities had resulted in its generation.

From the weighbridge records for the survey week, it was estimated that 12.1 tonnes of general waste were disposed of at the facility. Determining the actual weight to landfill was problematic, because some vehicles disposed of recoverable materials at the separate drop-off points after the vehicle had been weighed and before disposing of the residual waste at the tipping floor. In these instances the surveyor’s estimate of the load weight was used and the weighbridge records adjusted accordingly. A further complication was that some vehicles classified as ‘green waste’ at the weighbridge also disposed of residual waste at the tipping floor. Vehicles classified at the weighbridge as ‘green waste’ were not included in the total for general waste.

Table K5.2 shows the percentage of loads originating from each activity, the percentage of total weight, and the tonnes per week.

Table K5.2: Activity source of general waste, 29 May–4 June 2008

Activity source No. of loads surveyed % of loads % of total weight Tonnes/week
Construction and demolition 12 5 13 1.6
Industrial/commercial/institutional 80 33 55 6.6
Landscaping and earthworks 2 1 4 0.5
Residential 151 62 28 3.4
Total 245 100 100 12.1

Residential activity was the source of 62 per cent of all loads of waste, but these loads accounted for just over one-quarter of the total weight of general waste. This is due to a large number of residential waste loads being relatively small, such as when bags of domestic refuse are dropped off. One-third of all loads were generated by ICI activity, and these loads accounted for 55 per cent of the total weight. C&D loads, while representing only 5 per cent of all general waste loads, accounted for 13 per cent of the total weight. Waste from landscaping activity generated 1 per cent of loads and 4 per cent of the total weight.

K5.1.3 Primary composition of general waste, by activity source

The primary composition of the four activity sources of general waste is shown in Table K5.3. The secondary composition is given in Appendix K15.

Table K5.3: Primary composition of general waste, by activity source, 29 May–4 June 2008

Primary category C&D
%
ICI
%
Landscaping
%
Residential
%
Paper 0.3 9.5 0.0 12.2
Plastics 8.4 13.2 0.0 12.4
Putrescibles 0.5 25.0 12.4 22.1
Ferrous metals 3.7 5.5 0.0 6.5
Non-ferrous metals 0.4 0.9 0.0 0.8
Glass 3.1 12.2 0.0 7.3
Textiles 16.5 9.5 1.0 10.5
Nappies and sanitary 0.0 9.7 0.0 11.4
Rubble 36.8 3.9 78.3 3.4
Timber 23.1 8.2 8.3 10.8
Rubber 4.5 0.9 0.0 1.1
Potentially hazardous 2.6 1.5 0.0 1.5

Timber and rubble together comprised most of the C&D waste (60 per cent). There was also a significant proportion of textiles, mainly used carpet and underlay. ICI waste was more heterogeneous, with no single material comprising more than 25 per cent of the total. Food waste was the largest single component of ICI waste, reflecting the relative size of the hospitality industry in the region. Landscaping waste was primarily rubble (78 per cent), which was mainly soil. The largest component of residential waste was putrescible material (22 per cent) which included both food waste from domestic bag drop-offs and landscaping waste. Many residential loads carry waste from several activities, so small quantities of landscaping and C&D waste may be present in a load that was classified as being generated by residential activity.

K5.1.4 General waste, by vehicle type

For each vehicle load of waste disposed of on the tipping floor, the vehicle type was recorded. Table K5.4 shows the percentage of loads transported by each of the vehicle types, the percentage of total weight carried by each vehicle type, and the tonnes per week.

Table K5.4: General waste, by vehicle type, 29 May–4 June 2008

Vehicle type No. of loads % of loads % of weight Tonnes/week
Cars 142 58 18 2.2
Compactors 0 0 0 0.0
Front-loader trucks 0 0 0 0.0
Gantry trucks 0 0 0 0.0
Huka trucks 0 0 0 0.0
Other trucks 19 8 25 3.0
Trailers 84 34 57 6.8
Total 245 100 100 12.1

No compactors, front-loader trucks, gantry trucks or huka trucks disposed of general waste during the survey period. Almost 60 per cent of the loads disposed of on the tipping floor were carried by cars, but car loads accounted for only 18 per cent of the total weight. Many of these car loads comprised a small number of domestic rubbish bags. Trailers represented 34 per cent of all vehicle loads, but these loads accounted for 57 per cent of the total weight.

K5.1.5 Primary composition of general waste, by vehicle type

The primary composition of loads carried by the three main types of vehicles that disposed of waste is shown in Table K5.5. The secondary composition is shown in Appendix K16.

Table K5.5: Primary composition of general waste, by vehicle type, 29 May–4 June 2008

Primary category Car
%
Other truck
%
Trailer
%
Paper 11.2 6.8 8.6
Plastics 13.7 9.0 12.4
Putrescibles 31.4 23.8 15.5
Ferrous metals 5.0 2.4 6.7
Non-ferrous metals 0.7 0.4 1.0
Glass 4.9 15.9 7.6
Textiles 7.4 11.2 11.1
Nappies and sanitary 14.6 8.1 6.7
Rubble 4.1 15.4 11.3
Timber 5.3 6.2 14.8
Rubber 0.6 0.3 2.2
Potentially hazardous 1.3 0.5 2.2

K5.2 Overall waste to landfill

K5.2.1 Source of overall waste to landfill

The overall waste stream being disposed of at Kaikoura Landfill comprised the general waste stream, the private kerbside collection, and glass disposed of by Innovative Waste Kaikoura for landfill stabilisation (special waste). The composition of the overall waste stream was determined by combining information from the weighbridge records for the survey week with the results of the visual survey.

From the survey it was determined that kerbside refuse collections were being disposed of by a single private waste operator. Weighbridge records were used to calculate the weekly tonnage from this operator, and the weekly tonnage of general waste was also calculated from the weighbridge records. Because many small vehicle loads were not weighed by the weighbridge, it was necessary to assign average load weight figures for those vehicles. No glass was stockpiled during the survey, so the glass tonnage has been taken directly from the weighbridge records.

Table K5.6: Waste types to landfill, 29 May–4 June 2008

Waste type

% of weight

Tonnes/week

General

59

12.1

Kerbside collections

12

2.5

Special

29

6.0

Transfer station

0

0.0

Total

100

20.5

A total of 20 tonnes of refuse was disposed of during the survey period. This figure does not include loads of green waste, cleanfill or steel that were disposed of at the separate drop-off points. Of the 20 tonnes disposed of during the week, 60 per cent was general waste. The general waste included the drop-off of domestic refuse by residents.

K5.2.2 Primary composition of overall waste to landfill

The primary composition of the overall waste to landfill is calculated by combining the compositions of the three different waste types in the proportions shown in Table K5.6. The compositions of the three different waste types have been determined as follows:

  • general waste – as determined from survey results and shown in Section K5.1.1

  • kerbside collection – assumed to be the composition given in Appendix K1, which is based on the results of the previous audits of domestic kerbside refuse undertaken by Waste Not Consulting

  • special – the special waste is all recyclable glass.

The primary composition of the overall waste stream is given in Table K5.7 and Figure K5.2. The secondary composition is given in Appendix K17.

Table K5.7: Primary composition of overall waste, 29 May–4 June 2008

Primary category % of total Tonnes/week
Paper 6.8 1.4
Plastics 8.7 1.8
Putrescibles 17.8 3.7
Ferrous metals 3.4 0.7
Non-ferrous metals 0.6 0.1
Glass 35.2 7.2
Textiles 6.4 1.3
Nappies and sanitary 6.1 1.2
Rubble 6.7 1.4
Timber 6.5 1.3
Rubber 0.8 0.2
Potentially hazardous 1.0 0.2
Total 100 20.5

Figure K5.2: Primary composition of overall waste, 29 May–4 June 2008

Glass was the largest category of waste disposed of at the facility, comprising 35 per cent of the total. Putrescible material was the second largest primary classification of the overall waste stream with 18 per cent of the total. Most of the putrescible material was kitchen/food waste in kerbside refuse and ICI refuse.

K5.3 Discussion and analysis

K5.3.1 C&D waste

Loads of waste generated by C&D activity (see Section 2.6 for the taxonomy of C&D waste) were identified during the visual survey of the general waste stream. Kerbside refuse, the other waste stream besides general waste disposed of at the facility, contains negligible quantities of C&D waste. Special waste contains no C&D waste. The quantity of C&D waste in the overall waste stream is calculated in Table K5.8.

Table K5.8: C&D waste, 29 May–4 June 2008

Total C&D waste in general waste 1.6 tonnes (from Table K5.2)
Overall waste to landfill 20.5 tonnes (from Table K5.6)
C&D waste as proportion of overall waste to landfill 7.8%

Table K5.8 shows that C&D waste comprised 7.8 per cent, by weight, of the overall waste to landfill.

K5.3.2 Factors affecting waste generation and disposal during survey period

A range of factors affect the quantity and composition of waste disposed of at any individual disposal facility. Some of the factors considered to be relevant to the waste disposed of during the 29 May–4 June 2008 survey period are discussed below.

K5.3.2.1 Weather before and during the survey period

May 2008 was much cooler and drier than normal, with Kaikoura recording its third lowest mean daily temperatures on record.4 These climatic factors would have resulted in reduced vegetative growth. There were high winds and heavy rains on the weekend during the survey, which is likely to have resulted in a reduced number of vehicles using the facility.

K5.3.2.2 Tourism and construction activity

Tourism is a major contributor to the Kaikoura economy, and the tourism sector has been identified as a major waste generator. May falls in the main tourism season, but it would be expected that waste volumes would be less than in the February survey, when tourist numbers are higher.

Construction in Kaikoura might be scheduled to occur during the winter months to avoid disruption during the tourist season. The May survey included more C&D waste than the February survey, but less than the first two surveys in September and November.

K5.3.2.3 Individual waste generators

The quantity of waste disposed of at Kaikoura Landfill is sufficiently small for the composition to be changed significantly by the waste disposal behaviour of a single waste generator. The size of the residual waste stream at Kaikoura Landfill means that the composition may vary considerably from week to week, unlike at larger facilities.