By Alfred Twu
Today, there are two main types of recycling systems. Source separation, used in Berkeley, collects paper and containers separately. Single stream, used in most other Bay Area cities, mixes paper and containers all in one cart, with machines and workers separating them at the recycling center.
While often marketed as more convenient and easier for people to use, and credited with getting more people to recycle, single stream leads to contaminated materials. Previously, these were shipped to China for further sorting, but new regulations from China's government have banned this practice. The prices other markets will pay for these dirty materials is so low that many single stream recyclers now have to pay to move their materials. Some cities such as Milpitas and Windsor have switched to source separation, while others are landfilling recyclables.
With garbage and compost, we're going down a similar road. With compostables being one of the main divertable materials in garbage, some waste haulers are now looking at “mixed waste processing”. This takes garbage and mechanically separates some of the compostable materials, which are then put in an anaerobic digester. The problem is that this material is contaminated by garbage, and instead of producing compost, the end result is “compost-like output”, which is unsuitable for agriculture, as well as “solid recovered fuel,” which then gets burned.
While sounding “convenient”, mixed waste processing has the same basic flaw as single stream. Both create low-quality materials that are difficult to find economical uses for. Therefore, it's important that when planning for zero waste, we look beyond just the initial diversion rate, and also at the quality of materials.
How does your city handle waste? If it’s not source separation, consider writing to your city council and urge them to push for a switch!
Alfred Twu is chair of the Bay Chapter's Zero Waste committee and also the illustrator of the images above.