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M2 Results: 6–12 August 2007

M2.1 General waste

M2.1.1 Primary composition of general waste

The primary composition of the general waste is presented in Table M2.1 and Figure M2.1. The secondary composition, which includes all 22 categories, is given in Appendix M2.

Table M2.1: Primary composition of general waste, 6–12 August 2007

Primary category % of total
( ± 95% confidence level)
Tonnes/week
Paper 8.7% (±2.3%) 3.7
Plastics 8.7% (±2.7%) 3.7
Putrescibles 11.4% (±3.5%) 4.9
Ferrous metals 9.7% (±4.1%) 4.1
Non-ferrous metals 0.9% (±0.4%) 0.4
Glass 4.2% (±1.7%) 1.8
Textiles 4.0% (±2.3%) 1.7
Nappies and sanitary 0.7% (±0.2%) 0.3
Rubble 18.6% (±9.8%) 7.9
Timber 31.3% (±12.4%) 13.3
Rubber 0.5% (±0.2%) 0.2
Potentially hazardous 1.2% (±0.7%) 0.5
Total 100%   42.5

Figure M2.1: Primary composition of general waste, 6–12 August 2007

Timber was the largest single component of the general waste, comprising 31 per cent of the total. A majority of this timber was from construction and demolition loads. Rubble was the second largest primary component, comprising 19 per cent of the total. Half of the rubble was contained in two loads of concrete tiles and debris. Paper, plastic, putrescibles and ferrous metals all made up similar proportions of the general waste (between 9 and 11 per cent).

M2.1.2 General waste, by activity source

For the purpose of this report, general waste is the waste discharged at the Matamata Transfer Station that has not come from kerbside collections. Using the activity source categories (see Section 2.4), general waste therefore comprises waste from construction and demolition (C&D), industrial/commercial/institutional (ICI), landscaping and earthworks, and residential activities. During the survey period, data was gathered on 181 loads of general waste. 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 42.5 tonnes of general waste were disposed of at the facility. Table M2.2 shows the percentage of loads originating from each activity, the percentage of the total weight, and the tonnes per week.

Table M2.2: Activity source of general waste, 6–12 August 2007

Activity source No. of loads surveyed % of loads % of total weight Tonnes/week
Construction and demolition 24 13% 42% 17.7
Industrial/commercial/institutional 24 13% 19% 8.2
Landscaping and earthworks 15 8% 6% 2.5
Residential 118 65% 33% 14.1
Total 181 100% 100% 42.5

Residential activity was the source of nearly two-thirds of all loads of waste, but these loads accounted for only one-third 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. C&D loads, while representing only 13 per cent of all general waste loads, accounted for over 40 per cent of the total weight. Waste from landscaping activity generated 8 per cent of loads and 6 per cent of the total weight. A number of loads of green waste were disposed of on the tipping floor rather than at the green waste drop-off point, because the drop-off point was flooded and access was difficult for much of the week.

M2.1.3 Primary composition of general waste, by activity source

The primary composition of the four activity sources of general waste are shown in Table M2.3. The secondary composition and margins of error are given in Appendix M3.

Table M2.3: Primary composition of general waste, by activity source, 6–12 August 2007

Primary category C&D ICI Landscaping Residential
Paper 5.2% 16.8% 0.9% 10.0%
Plastics 5.9% 15.3% 0.9% 9.7%
Putrescibles 0.6% 12.6% 77.5% 12.4%
Ferrous metals 8.2% 10.9% 0.0% 12.7%
Non-ferrous metals 0.6% 1.5% 0.0% 1.1%
Glass 2.1% 9.0% 0.1% 4.9%
Textiles 1.9% 5.9% 0.0% 6.3%
Nappies and sanitary 0.0% 1.3% 0.1% 1.3%
Rubble 28.1% 7.2% 7.9% 15.1%
Timber 45.9% 16.5% 12.6% 24.8%
Rubber 0.5% 0.6% 0.0% 0.4%
Potentially hazardous 1.0% 2.4% 0.0% 1.2%

C&D waste was primarily composed of timber and rubble (74 per cent combined). ICI waste was more heterogeneous, with no single material comprising more than 17 per cent of the total. Paper (mostly cardboard packaging) was the largest single component of ICI waste, with 17 per cent of the total. Landscaping waste was primarily green waste (78 per cent) with timber making up about 13 per cent. The largest component of residential waste was timber (25 per cent), which included both fabricated items (such as furniture) and C&D timber. Note that many residential loads carry waste from several activities, so small quantities of C&D waste may be present in a load that was classified as being generated by residential activity.

M2.1.4 General waste, by vehicle type

For each vehicle load of waste disposed of on the tipping floor, the vehicle type was recorded. Table M2.4 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 M2.4: General waste, by vehicle type, 6–12 August 2007

Vehicle type No. of loads % of loads % of weight Tonnes/week
Cars 95 52% 12% 4.9
Compactors 1 1% 1% 0.5
Front-loader trucks 0 0% 0% 0
Gantry trucks 12 7% 39% 16.6
Huka trucks 0 0% 0% 0
Other trucks 12 7% 11% 4.8
Trailers 61 34% 37% 15.7
Total 181 100% 100% 42.5

No front-loader trucks or huka trucks disposed of waste during the survey period. Only a single compactor truck, other than those carrying kerbside collections, used the facility. Half of the loads disposed of at the transfer shed were carried by cars, but car loads accounted for only 12 per cent of the total weight. Many of these car loads comprised a small number of domestic rubbish bags. Although gantry trucks accounted for only 7 per cent of vehicle loads, they accounted for 39 per cent of the total weight. Trailers represented 34 per cent of all vehicle loads and 37 per cent of the total weight.

M2.1.5 Primary composition of general waste, by vehicle type

The primary composition of loads carried by the four main types of vehicles that disposed of waste are shown in Table M2.5. The secondary composition is shown in Appendix M4.

Table M2.5: Primary composition of general waste, by vehicle type, 6–12 August 2007

Primary category Car Gantry truck Other truck Trailer
Paper 12.3% 7.1% 9.0% 8.6%
Plastics 14.5% 9.2% 6.4% 6.8%
Putrescibles 20.7% 5.3% 9.9% 15.4%
Ferrous metals 10.8% 14.3% 7.0% 5.6%
Non-ferrous metals 1.6% 1.2% 0.8% 0.3%
Glass 6.7% 4.2% 2.8% 3.1%
Textiles 4.7% 5.1% 1.4% 3.5%
Nappies and sanitary 3.8% 0.2% 0.3% 0.3%
Rubble 6.2% 15.8% 16.8% 26.5%
Timber 17.5% 35.3% 44.8% 28.2%
Rubber 0.2% 0.9% 0.3% 0.1%
Potentially hazardous 1.0% 1.4% 0.5% 1.4%

M2.2 Overall residual waste

M2.2.1 Source of overall residual waste

Because there was no special waste, or waste from other transfer stations, being disposed of at Matamata Transfer Station, the overall residual waste stream comprised only the general waste stream and kerbside collections. The composition of the overall residual waste stream has been determined by combining information from the weighbridge records for the survey week with the results of the visual survey.

The survey found that kerbside collections were transported to the Matamata Transfer Station by two private waste operators as well as the council contractor. Using the weighbridge records, the tonnages of kerbside collection waste and general waste were calculated, and these are shown in Table M2.6. Because small vehicle loads such as trailers and cars were recorded by the weighbridge but not weighed, it was necessary to use average load weight figures for these vehicles.

Table M2.6: Overall residual waste types, 6–12 August 2007

Waste type % of weight Tonnes/week
General 48.3% 42.5
Kerbside collections 51.7% 45.5
Special 0% 0
Transfer station 0% 0
Total 100% 88.0

A total of 88 tonnes of refuse were disposed of during the survey period. This figure does not include loads of green waste or steel that were disposed of at the separate drop-off points. Of the 88 tonnes disposed of during the week, slightly over half was from kerbside collections and the rest was general waste.

M2.2.2 Primary composition of overall residual waste

The primary composition of the overall residual waste stream is calculated by combining the compositions of the two waste types in the proportions shown in the previous section. The compositions of the two waste types have been determined as follows:

  • general waste – as determined from survey results and shown in Section M2.1.1

  • kerbside collection – the assumed composition (see Appendix M1) for the kerbside collection was that determined by the sort-and-weigh audits undertaken at the Matamata Transfer Station in 2003/04 for the Ministry for the Environment’s SWAP Baseline Data Programme.

The primary composition of the overall residual waste stream is given in Table M2.7 and Figure M2.2. The secondary composition is given in Appendix M5.

Table M2.7: Primary composition of overall residual waste, 6–12 August 2007

Primary category % of total Tonnes/week
Paper 13.2% 11.6
Plastics 12.0% 10.5
Putrescibles 24.0% 21.1
Ferrous metals 7.4% 6.6
Non-ferrous metals 0.8% 0.7
Glass 5.2% 4.6
Textiles 4.7% 4.1
Nappies and sanitary 6.1% 5.4
Rubble 9.5% 8.4
Timber 15.7% 13.8
Rubber 0.3% 0.3
Potentially hazardous 1.0% 0.8
Total 100% 88.0

Figure M2.2: Primary composition of overall residual waste, 6–12 August 2007

Putrescible material comprised the largest primary classification of the overall residual waste stream, representing nearly a quarter of the total. A large proportion of the putrescible material was kitchen waste in kerbside collections. Timber was the second largest component, with 16 per cent of the total.

M2.3 Discussion and analysis

M2.3.1 C&D waste

Loads of waste generated by C&D activities (see Section 2.6 for the taxonomy of C&D waste ) were identified during the visual survey of the general waste stream. Kerbside collections, the other waste stream besides general waste disposed of at the facility, contain negligible quantities of C&D waste. The quantity of C&D waste in the overall residual waste stream is calculated in Table M2.8.

Table M2.8: C&D waste, 6–12 August 2007

Total C&D waste in general waste 17.7 tonnes (from Table M2.2)
Overall residual waste 88.0 tonnes (from Table M2.6)
C&D waste as proportion of overall residual waste 20.1%

Table M2.8 shows that C&D waste comprised 20 per cent, by weight, of the overall residual waste.

M2.3.2 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 most relevant to the waste discharged at the transfer station during the 6–12 August 2007 survey period are discussed below.

M2.3.2.1 Weather before and during the survey period

The August audit took place at the end of a very wet winter. This could have affected waste generation related to gardening and agricultural activity, given that vegetative growth would have been slowed by the conditions. The adverse weather conditions could also have resulted in reduced construction activity.

The weather immediately before the audit was also very wet, with very heavy showers resulting in the green waste drop-off area at the transfer station being largely flooded. As a result, much green waste was disposed of in the tipping shed instead of at the drop-off area. The combined result of these factors on green waste disposal can not be determined.

M2.3.2.2 Economic conditions

Reports of economic conditions in the Waikato for the June 2007 quarter are mixed. The Treasury website reports the following:5

The Rabobank rural confidence survey showed an increase in confidence in the agricultural sector between April and July. The percentage of farmers expecting the economy to improve in the next year increased from 22% to 40%. The survey was taken after the announcement of Fonterra’s increased payout for the 2007/08 season and dairy farmers were the most optimistic. Sheep and beef farmers were less pessimistic than in the previous survey.

Retail sales grew 1.2% in May (seasonally adjusted), reversing their dip of the same magnitude in April. The growth in sales was concentrated in supermarket and grocery stores (1.9%) and motor vehicle retailing (4.4%), the two largest store-types. Annual growth in total sales has averaged nearly 13% over the past 8 months in the Waikato region (approximately twice the national average growth rate), reflecting the buoyant dairy industry. Sales of motor vehicles have been particularly strong in that region.

However, the National Bank regional trends report is somewhat at variance with this analysis:6

Following two previous strong outturns, economic activity in Waikato retraced 0.3 percent in the June quarter. The region recorded a 13 percent fall in house sales, which was the second largest decline across the regions. Waikato recorded a large drop in consumer confidence, taking the relative level of household sentiment down to the second lowest reading across the regions. The number of commercial building consents issued in Waikato slipped 7.4 percent, dwarfing a 2.6 percent decline nation-wide. Retail sales eased 1.0 percent. Partially offsetting this were increases in employment, new car registrations and rural real estate sales.

The buoyant dairy industry may result in increased retail spending and construction activity in the medium term. However, the combined result of these factors on waste generation and disposal during the survey period can not be estimated.

M2.3.2.3 Individual waste generators

The quantity of waste disposed of at the Matamata Transfer Station is sufficiently small for the composition to be changed significantly by the waste disposal behaviour of a single waste generator. The surveyor noted that a local construction company was undertaking a significant project in Tauranga (some 50 kilometres away), but was disposing of the construction waste at the Matamata Transfer Station. This single waste generator accounted for at least 10 per cent of the C&D waste disposed of at the facility.