If it is not possible to get actual weights, you may still be able to generate reasonably accurate numbers by doing volume-to-weight conversions. To be included in the official ranked competition, schools must be able to track the volume of actual material collected. In other words, they must be able to say how many bins were emptied and approximately how full they were. For smaller carts you can pop the lids on a few and get a feel for how full they are on average and use this to multiply across all carts. For larger dumpsters, a visual inspection of each is necessary to mark down are they ¼ full, ½ full, ¾ full or completely full. You’ll also need to determine their actual capacity so that you can calculate the number of bins vs. capacity vs. how full they are to arrive at a total capacity.
Once you have determined the total volume capacity, you will need an average “per yard” or “per gallon” weight to use as a multiplier to estimate weight. The first and best option is to weigh sample bins to get an average weight. Collection haulers not willing to weigh every week may nonetheless be willing to do a dedicated campus route on one or two occasions to create these multipliers. If so, be sure to tag along to determine how many dumpsters are emptied on that route and how full they are so you can assign the number of gallons or yards to the weight. Another possibility: If recyclable materials are collected in bags, weigh 20 or 30 bags to get an average weight and then track the number of bags taken out each week going forward.
If you are not able to generate your own campus-specific sample weights as the basis for creating multipliers, the US EPA has generic volume-to-weight formulas to use as a backup. Note: because the weight of recyclables or trash can vary significantly from one location to the next, these EPA multipliers may not accurately reflect the actual weight of materials on a particular campus. Coordinators should use their judgment in deciding whether their actual materials are likely lighter or heavier and make adjustments as necessary. RecycleMania rules require schools to use a good faith best judgment in reporting all numbers even when relying on EPA, waste hauler or other 3rd party multipliers. If you have questions about this, contact RecycleMania for advice.