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Waste Indicators

Appendix B: Time consumption for comprehensive mapping

2 Quantities and treatment of different waste fractions

Below, the possibilities of setting up general calculation principles for estimates of waste quantities within the different material fractions will be discussed. In addition, the amount of time required for this purpose will be considered. To get an overall outline of the amount of time required for a mapping, considerations on time requirements for provision of LCA data will be included, see also Chapter 6 of the main report.

Mixed waste fractions, such as "domestic waste", consisting of a number of material fractions will be represented in calculations under the different materials and are not discussed as individual waste fractions. As a check of calculated quantities, total quantities of all material fractions must correspond to total registered waste quantities, incl. mixed fractions.

Appendix A contains an environmental screening of the different waste fractions. In the following, a review will be presented divided into material fractions with a view to estimating the amount of time required for provision of data for calculation of the proposed indicators.

2.1 Review of material fractions

2.1.1 Paper and cardboard

Annual statements of paper consumption and collection and recycling of paper appear from the statistics on waste paper from Waste Centre Denmark /39/.

Waste paper that is not recycled can be estimated based on statements in the above statistics. Therefore, it is assessed that there is no need for further statements of consumption of paper and cardboard.

2.1.2 Glass

Annual statements of consumption of glass packaging and collection and recycling of glass packaging appear from the statistics "Glass, bottles and cullet" from Waste Centre Denmark /18/. No statement of recycling of flat glass is available.

Waste glass packaging that is not recycled can be estimated on the basis of the statements in the above statistics. Therefore, it is assessed that there is no need for further statements of consumption of glass packaging. For flat glass there will be a need for a status, and this will take about ¼ to 1 man-week. It is assessed that the status should be updated every five to ten years.

2.1.3 Plastics

In the plastic packaging statistics, figures are available for collection of plastic packaging divided into the plastic types: LDPE, HDPE, EPS, PP, PET, PS and "Other plastics " /28/. In addition to packaging, there is recycling of production waste and to a minor extent of PVC. No statistics are available for these quantities that must be based on statuses.

The rate of collection, and thus quantities of plastic packaging not collected for recycling, is calculated in statements by comparing quantities collected with the supply of plastic packaging. This is possible, as the useful life of plastic packaging is so short that quantities becoming waste will correspond almost completely to consumption. For plastic packaging, thus, necessary data is directly available. For each plastic type it will be relatively easy to develop specific indicators that primarily based on energy consumption for production of the plastic type in question.

At European level plastic packaging constitutes around 57% of total quantities of plastic waste, incl. PVC /28/. For other waste plastic types, no current statistics are compiled, but these plastics – apart from production waste and PVC for building purposes – are almost exclusively incinerated or landfilled today.

"Other plastics", accounting for around 43% of total plastic quantities, consists of a large number of different plastic types that are very different as to energy consumption for production. For example, for the production of polyamide (nylon) around 130 GJ/tonne are consumed, whereas manufacture of polypropylene only consumes 30 GJ/tonne /15/. This means that "other plastics" in relation to indicators probably accounts for a larger part of the contribution from plastics than the 43% it constitutes quantitatively. Plastics to a large extent will derive from imported products such as electronics and vehicles.

It will hardly be possible to make annual statements, but composition of plastics may be estimated roughly on the basis of data from the Association of Plastics Manufacturers in Europe (APME). However, in all circumstances a more detailed survey of average composition of plastics will be necessary. Quantities of collected and recycled PVC will also have to be found in individual studies, as no annual statements are made.

At first it is estimated that it will be relevant to divide amounts into polyolefin (PE and PP), PVC, polystyrene (such as PS, XPS and EPS), PET/PBT, PUR (polyurethane) and other cast plastics (epoxy, phenol resins and polyester). In setting up the calculation principle it will be necessary to evaluate whether this division is expedient.

Detailed statuses of quantities of plastics for waste treatment are estimated to have scope per plastic type (or group of plastic types such as composite materials) corresponding to the mass-flow analyses carried out for metals. As there is only very little recycling apart from packaging plastics, however, statements will be simplified by the fact that for most types it will be sufficient to state total waste quantities without making a detailed distinction between treatment options and use of plastic products. An overall individual survey of use and treatment of the most important plastic types will require around 4 to 12 man-months. It is assessed that such a survey should be conducted every five to ten years.

It should be noted that statements for "other plastics" compared to statements for packaging plastics require a more detailed analysis, as the useful life for products is so long that it cannot be assumed that quantities for waste treatment in a given period corresponds to consumption.

2.1.4 Metals

As it appears from the example calculated, metals have significant weight in the total accounts.

Collection and recycling

In the ISAG statistics, all metals are listed together under "Iron and metals". The total metal fraction consists mainly of iron and steel, and a statement of quantities and treatment of the individual metals therefore must be based on other data sources.

For estimating quantities of metals recycled it will be necessary – similar to the aluminium example of Appendix C – to base statements on Statistics Denmark’s figures for imports/exports of scrap and production of secondary metals. Under the different code numbers in the imports/exports statistics composite products appear, so there will be some uncertainty associated with such a statement. For example, cables are found under "copper scrap", and mixed fractions of heavy metals from shredder plants are found under "zinc scrap". In the preparation of a general methodology this uncertainty can be reduced by stating the estimated rate of each metal for each code number.

Quantities remelted in Denmark are stated in the statistics for aluminium and steel. The uncertainty for this code number is relatively small. For lead there is more uncertainty associated with quantities remelted, as they to not appear directly from statistics. But quantities are very small compared to total quantities recycled. For other metals there is no significant production of secondary metals in Denmark.

As seen in the example of aluminium, the uncertainty of the statement in the mass-flow analysis has been assessed at ± 12%. In a statement based on general principles of calculation uncertainty must be expected to be somewhat larger for most metals. So it will not be possible to follow small changes from one year to the next, but only to see development trends over a longer period.

It is probably possible to set up a regular procedure allowing for an estimate of total quantities recycled on the basis of an extract from Statistics Denmark. Changes take place occasionally in the division of code numbers, so it will be necessary to check every year that calculations actually cover the relevant code numbers. In a rough estimate, it will require 1 man-week to set up a calculation principle for all metals. Subsequently, every year it will take around ½ to 1 man-day to collect data from Statistics Denmark.

Other treatment

For quantities incinerated or landfilled it is not possible to set up general calculation principles based on available statistics. Thus, it will be necessary to start with the most recent mass-flow analyses. For aluminium, copper, stainless steel (mass-flow analysis for nickel) and lead, analyses for 1994 are available. For iron and steel quantities for landfilling are so small that they may probably be neglected. For zinc no mass-flow analysis is available. It is relatively time-consuming to update mass-flow analyses, so it should be expected to use the same values for a number of years.

It might be considered to keep total quantities of metals constant, whereas quantities for incineration or landfilling are estimated as the difference between this quantity and quantities recycled. However, for most metals this difference is so small compared to uncertainties, that uncertainties associated with the difference would easily be ± 50% or more. Therefore, there seems to be no other possibility than to use statements in mass-flow analyses of quantities for incineration and landfilling respectively. In this way, significant changes in indicators (apart from "savings realised") can only be found through a revision of estimates of the mass-flow analyses.

The time required for preparing a detailed mass-flow analysis is in the range of 4 to 6 man-months for one single metal. If the purpose is only to estimate waste quantities divided into treatment options, the analysis may probably be carried out in less time, but 1 to 3 man-months per metal would still be necessary. The reason is that waste quantities must be estimated on the basis of a thorough knowledge of historical use of metals for all application areas. For most metals there are many minor sources of waste. For the heavy metals lead, cadmium and mercury it has been practice in the last decades to update mass-flow analyses every five to ten years. For zinc no analysis is available, whereas for other metals only one detailed analysis is available so far.

The amount of time required for updating quantities every five to ten years for all metals is 7 to 14 man-months, according to a rough estimate. It should be noted that updating mass-flow analyses can also take place as a part of other surveys, and that the time needed specifically for the calculation of indicators may thus be reduced.

2.1.5 Oil and chemical waste

Precise statements of both total waste quantities and quantities of recycled oil and chemical waste are available. As indicators do not cover environmental impacts, it will be possible to group oil and chemical waste in large groups and thus minimise work of developing LCA-based indicators. Resource consumption for production of oils and chemicals will primarily relate to energy resources, making it simpler to group several categories.

A minor part of oil and chemical waste is not treated as "oil and chemical waste", but it is assumed that such small quantities are involved that they can be disregarded.

Oil and chemical waste will only cover part of total consumption of chemicals, as chemicals ending up in finished products will not be part of the statement. It is estimated to be unrealistic to make statements covering these chemicals.

2.1.6 Automobile rubber

The ISAG system contains information on total quantities of automobile rubber collected. As tyres today must be collected separately it is assumed that statistics cover quantities actually treated, and that relatively small quantities are treated in other ways. ISAG statistics may be supplemented with the tyre trade’s statistics of the take-back scheme and statistics of retreading and granulation of rubber powder /40/. Large tyres (trucks and tractors etc.) have only been covered by the rules, and thus statistics, from 1999. The decisive factor in the calculation will be to "value" materials substituted in recycling.

Small quantities of automobile rubber are assumed to be treated as bulky waste or shredder waste. At present no statement is available, and thus quantities will have to be estimated on the basis of a status. As a rough estimate, such a status will require ½ to 1 man-week.

2.1.7 Concrete, tiles and asphalt

Quantities of concrete, tiles and asphalt recycled appear from the ISAG. In direct reuse of asphalt for new paving on site, treated quantities need not be reported to the ISAG. Waste Centre Denmark has carried out a more detailed survey of management of construction and demolition waste /32/.

Material-flow statistics are special statistics that are also prepared for construction and demolition waste /32/. Quantities generated annually also appear from these statistics, providing the basis for calculating how large a proportion of construction and demolition waste is recycled. In 1997 more than 91% was recycled as backfilling material.

Overall, there will only be a very small uncertainty in statements of quantities and waste treatment, and it is estimated that there is no need for further statements. The decisive factor for these material fractions will be to "value" materials substituted in recycling.

2.1.8 Wood (incl. wood plates)

Wood collected separately and registered in the ISAG primarily covers production waste and pressure-impregnated wood. Reuse carried out, for example, in demolition enterprises, will not be registered, but is estimated to account for a very small part of collected quantities of wood treated as waste. In an indicator system not covering toxicity it is estimated that there is no need for a division into impregnated wood and other wood.

There are no statements of quantities of wood and wood plates incinerated or landfilled. Quantities must be estimated based on statuses. As there is presumably no large difference between energy recovery upon incineration, or recycling of wood, for example into wood plates, uncertainties in these quantities will hardly have a large impact on the overall indicator calculation. Therefore, the status can be made as a relatively rough estimate. A significant part of wood removed from buildings will be removed by demolition enterprises, and it is assessed that total quantities can be estimated on the basis of information from demolition enterprises and waste management companies. A rough estimate of total quantities will require about 1 to 2 man-weeks.

2.1.9 Other building materials

Other building materials cover plasterboard, insulation material, roofing slabs, flooring etc. At present there is no statement available of quantities treated by recycling or in other ways. Minor recycling of plasterboard takes place, but apart from this such waste is mostly landfilled.

A rough statement of quantities will have to be prepared. It is estimated that a rough statement for all materials can be made in ½ to 1 man-month.

2.1.10 Garden waste, food waste/other organic

Quantities of garden waste, food waste/other organic collected for recycling appear from the ISAG. In relation to the proposed indicators it will especially be relevant to distinguish between recycling for animal fodder and other recycling. This distinction is possible on the basis of ISAG data.

Total quantities of organic waste are not currently stated, but can be found in individual status reports. In relation to indicators for energy and resources, waste treatment of organic waste will hardly have a large impact. The calculation principle of calculating consumption for substitute materials is not assumed to apply to food waste. A status of quantities of garden waste, food waste and other organic waste is estimated to require ½ to 1 man-week.

2.1.11 Soil, gravel and stone

Soil, gravel and stone for recycling appears from the ISAG. In relation to the proposed indicators, treatment of soil, gravel and stone will hardly have a significant impact, and it is estimated that there is no need for further statements of these waste quantities.

2.1.12 Sludge, flue-gas cleaning products, incineration slag and energy recovery from incineration

Total quantities of sludge, flue-gas cleaning products and incineration slag disposed of by recycling and landfilling appear from the ISAG.

In a calculation covering all relevant treatment options for the different material fractions (Model A), incineration slag and energy recovery from incineration will be represented through the material fractions resulting in the generation of slag and energy. Therefore, they should not be included separately in the calculation.

In a calculation only covering recycling (Model B) it will only be relevant to include the quantities of incineration slag that are used for building and construction purposes and energy recovery from incineration. This avoids having to divide waste for incineration into the different material fractions. Total energy generation at incineration plants appears from the annual statistics on energy-generating plants from the Danish Energy Agency.

It is estimated that there is no need for further statements of these fractions.

2.1.13 Other

In the ISAG statements, a number of material fractions will only appear in mixed waste fractions, as in the waste management system there is very little collection and recycling of them. Materials in question are ceramics, textiles, rubber (excl. automobile rubber) etc.

The statements only cover main materials, whereas chemical products in main materials are not covered. Chemical products that may constitute a significant part of total waste quantities are paints/varnish, joint filler, putty, and printing inks.

Apart from rubber it will hardly be possible to recycle these materials significantly, and the question is how important it is to carry out the calculation. If there is an interest in having a measurement for energy and resource consumption for the manufacture of materials treated, however, it is relevant to include these materials.

If there is a wish to include the most significant main materials, a status must be prepared for each material group. It is estimated that rough statuses giving total quantities without a detailed division into areas of application can be carried out in ¼ to 1 man-month.

2.2 Total amount of time required

Information on data sources is in Table 2.1. It is seen that for a number of materials it will be necessary to supplement information from the ISAG with material-flow statistics or similar statuses of total quantities treated. It is estimated that statuses should be updated every five to ten years.

Time required for calculation of indicators will largely depend on whether a complete statement of waste impact (Model A in main report) should be made, or only a statement of savings realised (Model B).

It is estimated that carrying out statuses will account for the largest part of time required for setting up a total calculation principle and provision of quantitative data for making the first calculation (excl. life-cycle based factors). Total time required for updating statuses has been estimated in Table 2.1 to 12 to 30 man-months. In the first calculation some time can be saved if existing mass-flow analyses from 1994 are used, but as there is also a certain time requirement for setting up the overall calculation principle, the amount of time required is still estimated to be in the range of 8 to 20 man-months.

If a status has been made, the annual statement of savings realised (Model B in main report) is estimated to require around 1 to 1½ man-months. A significant part of the time is needed for collecting and checking data on metals from Statistics Denmark.

If no status has been made, Model B can still be carried out. However, in this case it will require 3 to 5 man-months plus 2 months for the LCA data, a total of 8 man-months for the first calculation.

Table 2.1:
Data sources for quantitative data ¹⁾

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Table 2.2:
Approximate amount of time required for carrying out statuses