Contamination plagues the industry
The Sierra Processing facility processes 12,000 tons of recyclables each month. Fifteen percent of what comes in on the trucks ends up as trash in the landfill. This includes contamination like plastic bags, solid waste, non-recyclable plastics, and a small portion of recyclables that are just too contaminated to cost-effectively sort. For reference, the national average is about 25%.
Which brings me to glass. This was the most disappointing, disheartening, part of the tour for many of us. While infinitely recyclable in theory, sorting facilities hate glass. Glass has a negative value (they would have to pay to recycle it), small pieces are everywhere and pose a risk to employees, and it wears out the sorting equipment. The glass bottle you put in your bin at home is typically broken into small pieces by the time it gets to the end of the processing line (see photo to the left). The small pieces of glass are so contaminated with bottle caps, shredded paper, and other small bits that it really has no market. To remove more of that contamination would be extremely labor and cost intensive, so this material is repurposed for things like replacing gravel as a road substrate in the local landfill. In addition, sand is such a cheap raw material that most new glass is made from sand rather than recycled old glass. Note: this does not apply to glass bottles that are taken back for their $0.05, because they do not have the contamination issue that single-stream recycling has. In fact, they told us that expanding bottle bills to include more glass would actually help them. Though they also noted that expanding the bottle bill to include additional high-value plastics would actually hurt these processing facilities because the bulk of what would be coming into the facility would be items with a low market value.