Contamination is the single biggest day-to-day challenge for a composting facility. A clean stream produces a clean product. A dirty stream means the finished compost has to be screened harder, sold for less, or — in the worst cases — landfilled after weeks of processing.
The usual offenders
- Conventional plastics: produce bags, snack wrappers, plastic film, water bottles
- Produce stickers (PLU labels) left on peels and cores
- Glass and metal: jar shards, foil, bottle caps, cutlery, twist ties
- “Biodegradable” items without BPI certification
- Latex and nitrile gloves
Why a few pieces matter
When plastic film goes through a grinder, it doesn't disappear — it shreds into small flakes that get distributed evenly through the whole batch. Stickers do the same thing. By the time the finished compost is being bagged or spread, those flakes are visible to the eye, and any facility selling to organic growers has hard limits on how much of that they can tolerate.
The fix is upstream: clear signage at the bin, a quick training pass with staff, and a once-a-week walk-by from a manager. We provide the signs and the training when you start service. See the “Goes in / Keep out” guide on /how-it-works for the specifics.
