There is waste data and there is waste data. Good quality waste data is required by organisations aiming to achieve waste minimisation and recovery targets. Unlike energy and water, where meter recordings can be taken on the last day of the month, obtaining waste data is much more complex and there are many opportunities for error.
When it comes to understanding your organisation’s baseline or tracking performance against targets, knowing the source and process for collecting the data is essential to appreciating the accuracy (and limitations) of the information provided.
The sources of waste data are typically from waste service provider invoices and/or monthly reports. Some waste service providers provide an excel spreadsheet stating the monthly weight/volume and cost of each stream collected. It is not necessarily clear in the spreadsheets which units are used (weights, volumes, number of bins) and some service providers apply their own conversion factors in order to estimate weights from bin volumes.
Waste service providers collect waste by mechanically lifting and tipping receptacles containing waste or recycling into trucks. Sometimes the vehicles are fitted with scales to weigh each bin as it’s tipped, which is generally relatively accurate (assuming the scales are well-calibrated). However, often the weight of waste or recycling is estimated by multiplying the total volume of the bin/skip by a conversion factor for that material stream. This creates errors, if the bin is only partially full, which can often be the case.
Whether bins are weighed or not, it’s important to be mindful that we aren’t receiving a measure of what was actually in the bin, for example non-recyclables in a recycling bin. So the data could be mis-reporting the amount of recycling. Even worse, the contamination could be so bad that the load could have ended up in landfill and not actually sent for recycling.
Some cleaning companies weigh bins on site. This is good practice in commercial offices where individual tenants want to know how much waste they generate and recycle. This internal data can be used to verify the data that waste service providers provide. This method also potentially provides an opportunity for the cleaners to inspect the bin contents and note contamination or other problems.
Sometimes there isn’t any data reported. This is especially the case if the council provides the collection services and your organisation pays for the service as part of the rates. In this case, an estimate based on bin volumes, numbers and collection frequencies is as good as it will get.
As well as having good quality waste collection data, it is also important to know where the waste from your building, site or organisation actually goes. General waste should be going to a landfill facility (or waste to energy facility) that is properly licenced to accept putrescible waste. Commingled recycling should go to a Materials Recovery Facility (MRF) for sorting, baling and selling to secondary processors to recover the materials (cardboard, paper, certain plastics) into feedstock for manufacturing processes. The MRF’s will sort and bale only those materials they can sell. Items where there is no market will be treated as contamination and go to landfill (often, this includes: PVC, biodegradable packaging and polystyrene). If the recycling from your organisation is not going where it should be going (or reported to be going), this can be a reputational risk for organisations.
Having a written process for obtaining the data, a user-friendly spreadsheet and a person in the organisation who is responsible are all good practices that will keep your data reporting smooth and accurate. Depending on the size of your organisation, there are software or apps for recording and monitoring waste data.
Below is a check for good quality waste data:
- Clear units – do the numbers represent tonnes, kg, number of bin lifts, total volumes?
- Calculation explanations – how are the numbers derived, bin lifts, scales on trucks etc.?
- Are any conversion factors applied? If so, what are they?
- Where does each material stream go? Can your service provider confirm it has been recycled or disposed of legally and safely? Can they provide dockets or other documents?
- Can the data be easily analysed to inform tracking against targets or imported into business systems?
- Is there any reporting of contamination or other problems?
Tracking waste data isn’t just about collecting numbers for reporting. Waste data is critical in understanding if the recycling initiatives you’ve implemented are actually helping to achieve your targets and identifying what you should be tackling next. Monitoring the data will also identify if you are being charged correctly by the service provider and that you’re not simply paying them to tip air into their trucks!
With carbon accounting here and waste tracking legislation still to come to Australia, collecting, trusting and verifying the data you are using to report against targets and knowing where your waste ends up are important habits to get into. Organisations are continually being required to implement better due diligence and supply chain audit processes and reporting. It is worth noting that most European countries have detailed legal reporting requirements for the chain of ‘ownership’ of waste from generator to disposal and also increasingly stringent ‘Duty of Care’ laws (just because the waste has left your building, you are still responsible for correct disposal).
It is no surprise that the old saying ‘you can’t manage what you don’t measure’ applies to waste just as much as any other aspect of running an organisation. Don’t be afraid to look at what the numbers on your waste reports really mean, after all, they are the key to helping you improve performance and even possibly save money!