Tool for measuring the recovery rates in CDEW MRFs

Transcription

1 Guidance notes Tool for measuring the recovery rates in CDEW MRFs Guidance notes for the Site-Specific Waste Analysis Tool (SSWAT) to measure recovery rates of construction, demolition and excavation waste (CDEW) at waste transfer stations and material recovery facilities. Project code: MRF121 ISBN: Research date: February to March 2009 Date: August 2009

2 WRAP helps individuals, businesses and local authorities to reduce waste and recycle more, making better use of resources and helping to tackle climate change. Document reference: WRAP, Site Specific Waste Analysis Tool guidance notes (WRAP project MRF121). Finalised by Mark Collinson, WRAP, Banbury Written by: Stephen Slater Front cover photography: Site Specific Waste Analysis Tool (SSWAT) WRAP and Oakdene Hollins Ltd believe the content of this report to be correct as at the date of writing. However, factors such as prices, levels of recycled content and regulatory requirements are subject to change and users of the report should check with their suppliers to confirm the current situation. In addition, care should be taken in using any of the cost information provided as it is based upon numerous project-specific assumptions (such as scale, location, tender context, etc.). The report does not claim to be exhaustive, nor does it claim to cover all relevant products and specifications available on the market. While steps have been taken to ensure accuracy, WRAP cannot accept responsibility or be held liable to any person for any loss or damage arising out of or in connection with this information being inaccurate, incomplete or misleading. It is the responsibility of the potential user of a material or product to consult with the supplier or manufacturer and ascertain whether a particular product will satisfy their specific requirements. The listing or featuring of a particular product or company does not constitute an endorsement by WRAP and WRAP cannot guarantee the performance of individual products or materials. This material is copyrighted. It may be reproduced free of charge subject to the material being accurate and not used in a misleading context. The source of the material must be identified and the copyright status acknowledged. This material must not be used to endorse or used to suggest WRAP s endorsement of a commercial product or service. For more detail, please refer to WRAP s Terms & Conditions on its web site:

3 Contents 1.0 Scope, definitions, assumptions Scope Definitions Assumptions Recovery rate reporting detail Guidance notes Overview Setting up the tool Setting macros Material conversion rates Material recovery rates Setting the conversion factors and material recovery rates Setting the tool to match the screen format...7 Using the tool... 8 Glossary CDEW EWC LOW MRF WTS Construction, demolition and excavation waste European Waste Catalogue List of Wastes Materials recovery facility Waste transfer station SSWAT Recovery Rate Tool Guidance Notes 3

4 1.0 Scope, definitions, assumptions 1.1 Scope The SSWAT tool calculates the recovery rates of construction, demolition and excavation (CD&E) waste at Materials Recovery Facilities (MRFs) and Waste Transfer Stations (WTSs) on a consignment specific basis. It assists Waste Management Contractors (WMCs) with their reporting of recovery information to construction clients, and relates to the WRAP Halving Waste to Landfill reporting requirements. 1 These guidance notes have been produced in order to assist in the use and understanding of the tool and its functionality. 1.2 Definitions Waste: All materials leaving the construction project site. 2 Recovered materials: The portion of a load of segregated or mixed waste received at a WTS or MRF that is re-used, re-manufactured, recycled, or used for energy generation, and therefore not disposed of in landfill. 3 Recovery rate: The weight of materials recovered at a WTS or MRF site, expressed as a percentage of the weight of waste materials received. This is broken down by material category. The overall rate for the WTS or MRF includes that for both segregated and mixed waste inputs. For other definitions, see WRAP document Detailed guidelines for UK Contractors Group companies to measure and report construction waste (January 2009) Assumptions The tool is designed to assist WMCs in reporting the specific recovery rates of all materials received from a construction company, whether received in a mixed waste or site-segregated skip. In order to do this effectively, and without unnecessary overhead a number of assumptions must be made: All waste transported to a WTS or MRF is inspected on collection or receipt. Segregated waste is suitable for onward shipment to the re-processor with no, or only minimal, sorting. If contamination is present in a segregated container, the MRF operator will either remove the offending articles so that the waste can be treated as segregated, or pass the waste through the sorting line as Mixed waste. The tool has boxes for entering the customer s name, the customer s site, a unique load number and the date. The need to fill all of these boxes is optional. The unit of measure is tonnes. The tool gives standard conversion factors to convert volume to weight. 1.4 Recovery rate reporting detail The tool can assist in the reporting of waste in a number of ways: Per container load of waste received; By material type; and Per customer/project/construction site (by aggregation of reports by the MRF Operator). 1 WRAP document Detailed guidelines for UK Contractors Group companies to measure and report construction waste (January 2009) 2 Environment Agency Position Statement Definition of waste: Development of industry code of practice. 3 Recovery may include the use of materials in the engineering of landfill cells, or as daily cover or road making at landfill sites. 4 SSWAT Recovery Rate Tool Guidance Notes 4

5 2.0 Guidance notes 2.1 Overview Most CDEW MRF operators are able to provide their waste-producing customers with waste recovery rate data based on the average recovery ratios at the MRF. Increasingly however, the construction industry and its clients require material-specific data based on waste from each project or construction site. One, highly accurate method of measuring waste recovery by material and by customer involves: stockpiling the waste from each customer; stopping and cleaning the sorting line; then running the stockpile through the line, measuring the inputs and outputs. This disruption to a MRF s operation is impracticable and expensive and is only offered to specific customers on a sampling basis. This tool therefore has been designed to take the MRF s existing performance data and to apply that data to the customer s specific container contents. In this way, reports on each consignment s contents can be provided by the MRF to the construction contractor, including the tonnage of material recovered and therefore landfill avoided due to the MRF s operation. The list of materials included in the tool has been arrived at by consultation with representatives from the construction and waste management industries. Nominal List of Waste 5 (LOW) Codes are given against each material. A comment box has been included with each LOW code in order to provide a more extensive list of materials that fall into each code category. The comment box for any material can be viewed by placing the cursor over the relevant material description. Before starting, the macro settings in Excel need to be set to Medium in order to enable the macros in the tool. The macro itself exists only to allow the user to reset the sheet. If the user prefers to disable the macros this will not prevent the tool working, but any previously entered values will need to be deleted manually. The method uses a visual assessment of the percentage - by volume - of each key waste material in each waste consignment. This works for any size or shape of container used for storing and transporting waste from the CD&E site to the MRF, and allows for mixed or segregated containers. The assessment of volumes may be carried out by the customer s representative at the construction site, by the collection driver, by the operative at the MRF tipping floor, or by any combination of these, in order to arrive at a best overall assessment. The nominal volume of the container and its net weight are taken from the weighbridge record, and recorded. The tool then calculates the approximate weight of each material. Note that the tool incorporates a number of sense-checks that will flag up error notices if the data input is obviously incorrect. Examples of such errors are: Percentages input not adding to 100%; Calculated volumes of materials being overwhelmingly greater than the capacity of the container; or Letters input in numeric-only fields rather than numbers. The tool applies pre-set volume to weight conversion factors for each material then calculates the recovery weight of each individual material stream. The volume to weight conversion factors built into the tool are based on industry accepted Environment Agency figures but can, if required, be re-set by the MRF before using the tool. The tool then adds the individual material recovery weights to arrive at an overall recovery weight for each consignment. The weighbridge ticket and transfer note numbers can also be tied in with the reported recovery rate for each consignment, and the calculated recovery rate can be included on the Waste Transfer Note, leading to greater transparency and traceability. 5 Previously known as EWC (European Waste Catalogue) codes. SSWAT Recovery Rate Tool Guidance Notes 5

6 3.0 Setting up the tool 3.1 Setting macros On opening the tool, choose Enable Macros. As noted in Section 2.1, it is recommended that the macro settings in Excel are set to Medium in order to enable the macros in the tool. To do this, choose Tools in the Menu Bar, then Macro, then Security. In the Security Level tab set the level to Medium. 3.2 Material conversion rates The visual assessment of each material in a mixed waste container means estimating what percentage of the load s volume is taken up by each material. To convert these volumes into weights, the tool uses a standard conversion factor for each material, based on Environment Agency (EA) data. It is possible to replace the EA conversion factors with your own figures if you so wish, although caution should be exercised as the EA data is generally accepted across the industry. The methodology for re-setting these figures is set out in section Material recovery rates The tool needs to be set up with the MRF s average recovery rates for each key output material or recyclate. You might want to assume 100% recovery from segregated consignments, but only if you regularly receive segregated loads which are free from contamination. For materials that are normally recyclable, but which are found to be unsuitable (e.g., wet cardboard), you should enter zero recovery rates against Other (non-recyclable) Whether the incoming waste stream is segregated or not, for best results use accurate material-specific recovery figures to set up the tool. Base them on the efficiencies of the recovery processes in use at the facility. You may already have an idea of these material-specific recovery rates for your MRF. If not, or if you want to make sure they are accurate, calculate them as follows: Record each consignment weight (from the weighbridge). Assess the ratios of material streams in the incoming waste stream for a period of time (as long as is practical). Record the weights of each separate incoming material within all waste containers. The total material tonnage input to the MRF is the sum of these records. Either: Record the output weights of each recyclate material from the weighbridge records during the same period. The ratio of the input to the output weights will give you a close estimate of specific material recovery rates. Or: Carry out waste composition analyses of samples of the residual waste containers being sent to landfill. The ratio of the input weight to weights of recyclable materials found in these samples represent the losses in recovery which will in turn give you the recovery rates for each material. Once you have reliable material-specific recovery rate data for your MRF, input them into the tool (two columns under Proportion of this material diverted from landfill in : Mixed consignments % and Segregated Consignments % ). The method for re-setting these figures in the spreadsheet is set out in section 3.4 SSWAT Recovery Rate Tool Guidance Notes 6

7 3.4 Setting the conversion factors and material recovery rates To set or re-set the conversion factors and the recovery rates, the tool spreadsheet needs to be unprotected. To do this, choose Tools in the Menu Bar, then Protection, then Unprotect Sheet. All figures in the column headed Volume to weight conversion factor, and the two columns headed Proportion of this material diverted from landfill in: may then be changed to suit local operating conditions. Once this is done, the tool spreadsheet needs to be re-protected before issue to the user. To do this choose Tools in the Menu Bar, then Protection. In the tab ensure that Protect worksheet and contents of locked cells is ticked and that Select unlocked cells only is also ticked. The tool is now ready for use. 3.5 Setting the tool to match the screen format If the spreadsheet is currently too large for the screen you re using, click on the button Press to fit this chart to the screen. This will resize the spreadsheet so that the whole of the sheet can be viewed all at once on any sized screen. SSWAT Recovery Rate Tool Guidance Notes 7

8 4.0 Using the tool To clear the sheet of any previous entries, click on Press to clear all input data. (This action does not delete the Customer, Date and Site boxes, which must be deleted manually if required) Important: Data may only be input in the white boxes on the tool. For each container of waste received: In the boxes at the top of the sheet enter the Customer Name, Date, customer s Site Name and an appropriate reference number for the consignment (this may be the transfer note, weighbridge ticket number or the vehicle registration number). Stage 1. In the box to the right of the Stage 1 box, record the nominal capacity of the container in cubic yards or cubic metres. Stage 2. In the box to the right of the Stage 2 box, record the net container weight from the weighbridge in tonnes, to 2 decimal places. Stage 3. Click on the white box to the right of the Stage 3 box. Click on the arrow to reveal a drop down menu. From the drop down menu select either Segregated if the site has a segregated skip policy or Mixed if the container contains un-segregated mixed waste. If Mixed is selected, you must assess the volume of each material stream in the consignment as a percentage of the total amount of all materials in the consignment. Record these percentages in the appropriate white boxes in the column headed Estimated volume in container (%). Clearly, these must add up to 100% even if the container is not full, or, indeed, has been over-filled. It is accepted that such assessments can only be accurate to multiples of 5% or 10%. Be sure to record the percentage volume of any material that is normally recyclable, but which is found to be unsuitable for recycling, against Other (non-recyclable), rather than against its nominal material category. If Segregated is selected, a new box appears titled Stage 3 (cont). Click on the white box to the right of this, then click on the arrow to reveal a new drop down menu which gives a list of possible materials in the container. From the drop down menu select the specific material, or Other (may include recyclables) or Other (non-recyclable). The tool will automatically identify the material in the spreadsheet, apply its recovery rate and record this as the Overall waste consignment recovery percentage. Notes on mixed consignments: Estimating the contents of every mixed waste consignment may not be practical for safety or economic reasons, so consider making sample assessments, say one in three containers, or perhaps at different phases of larger CD&E projects. If you use sampling, you must apply the same percentage recovery figures obtained for the sample to each container not sampled. Alternatively, ask your CD&E customer to provide information on the contents of a full mixed consignment ready for collection. Don t necessarily rely on this information: do your own assessment once the container is tipped at the MRF. Ideally, spread the material on the tipping floor to help the analysis, and take photos as a back up. SSWAT Recovery Rate Tool Guidance Notes 8

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