Three waste bin icons, with text to the side that reads “Five Reasons Why The Diversion Metric Does Not Measure Zero Waste”.

For the last few decades, international and US organizations have collectively understood the standard definition of “Zero Waste” to mean: “Achieving 90% diversion from landfills and incinerators.” The overwhelming majority of institutions that set a goal of achieving Zero Waste rely on the diversion metric as the measurement tool they are tracking to achieve their goal.

The diversion metric is a seriously flawed tool and should be universally rejected as a measurement for zero waste. While the metric can serve useful as part of a larger data set, it DOES NOT measure a holistic zero waste system. Here’s why:

1. The diversion metric doesn’t measure waste reduction.

Let’s say your current waste stream is sending 500 tons to landfill and 500 tons to recycling and compost. In this scenario you would have a 50% diversion rate.

One of your challenges is that you are experiencing high rates of contamination. You might have 500 tons of recycling and composting, but those bins are heavily contaminated with disposable plastics that are neither recyclable nor compostable, effectively rendering the material unusable at those facilities. So you build the system to switch out those items in favor of reusable containers and you entirely eliminate all of those disposable items. Now, your institution reduces 50 tons of waste from each of the three streams by eliminating single-use plastic – that’s great, right? But, if you run the numbers, reducing a cumulative 100 tons from the “diversion” category (i.e. compost & recycling) and 50 tons from landfill would actually DECREASE your diversion rate.

The diversion rate doesn’t provide the proper incentives for waste reduction; it incentivizes increasing recycling and compost streams, no matter the value of the material in those streams.

A chart that represents how, even when 150 tons of waste are reduced between two years, the diversion rate remains about the same.

2. The diversion metric doesn’t accurately represent waste generated per person.

An institution could be recycling 100% of all recyclable materials but still be increasing the total amount of waste per person. Additionally, many institutions have the ability to skew the metric, making it difficult to compare institutions based on this metric alone. For example, many institutions count Construction and Demolition materials as part of their recycling streams for items like wood, metal, and concrete – while others do not. Similarly, some institutions that have farms and agricultural centers can count organic disposal and manure as part of their compost stream – while others do not. If the institution is also calculating a metric based on waste generated per person, these materials can heavily skew that metric.

While it is important for these materials to be recycled and composted properly, measuring the overall effectiveness of an institution’s entire waste reduction system simply by weighing the institution’s outputs can result in skewed data because some materials are much heavier than others.

3. The diversion metric is based on weight.

Measuring our efforts to achieve waste by measuring the weight of the material is an ideology rooted in our economic understanding of waste management. We pay for waste by weight – all waste disposal, recycling, and compost companies charge by the ton – so that’s how we think about success.

As illustrated by the example above, inherently heavy waste streams can drastically skew your diversion rate. Compostable materials like soiled paper products, food scraps, animal manure, etc., are extremely heavy and can give the impression that your campus is performing well in regards to diversion. On the other hand, plastic packaging and other non-recyclables can be deceptively light and do not truly represent the amount of landfill items that are still being generated at our institutions. For us to truly measure zero waste, we have to think about the impact materials have on a holistic scale – and then build systems and infrastructure to handle them properly.

4. The diversion metric could be partially to blame for our current recycling crisis.

The proliferation of single-use disposable plastics that are not recyclable or compostable has caused a mass amount of confusion over what belongs in what bin, and forces the majority of us to “wish-cycle” (“if it’s plastic I’ll recycle it and assume they know how to handle it”). This causes contamination, and is forcing haulers to send materials that are otherwise recyclable or compostable to landfills or incinerators.

Measuring our success towards zero waste by using the diversion metric has encouraged this type of behavior. Institutions need to focus on how to clean up their recycling and composting streams by eliminating items that cause confusion and contamination through streamlined purchasing.

5. The diversion metric incentivizes recycling over reuse.

A holistic approach to measuring and tracking zero waste would incentivize projects that are higher up on the zero waste hierarchy. However, the diversion metric only incentivizes  recycling and composting – efforts that are towards the bottom of the pyramid. There are so many other things we should be focusing on before we even get to recycle/compost. For example, reuse initiatives such as thrift shops, antique stores, sharing shelves, community swap-meets, etc. keep materials out of the landfill, but the diversion metric does not incorporate these efforts into its calculation.

Some other examples include reducing production of plastic and hard-to-recycle materials, completely rethinking how companies manufacture and package products, holding repair fairs, and many more!

Image called the Zero Waste Hierarchy, with an upside down triangle that is split into different sections. At the top of the hierarchy (meaning the base of the triangle), there is Rethink/Design, followed by Reduce underneath it, and Reuse underneath Reuse. The rest of the hierarchy goes like this: Recycle/Compost, Material Recovery, Residuals Management such as biological treatment and stabilized landfilling, and Unacceptable forms of waste solutions such as waste deregulation, incineration, and waste-to-energy.

Image Credit: ZWIA & Energy Justice Network

At the Post-Landfill Action Network (PLAN), we have been working for the last few years to build a new benchmarking tool that will allow an institution to establish a holistic understanding of their zero waste system – following the zero waste hierarchy for all materials handled. The Zero Waste Atlas framework is unique because it can be customized to each campus/institution, and it provides a scoring-based assessment on the existence of policies, infrastructure, logistics, communication, and standardization of collection strategies. You can learn more about Atlas here, or ask your Campus Coordinator about it!