How it works
At a MRF or compost facility, staff sample inbound loads or audit them and estimate how much of the material does not belong. The contamination rate is that share, often calculated as the weight of unacceptable items divided by total weight. Facilities may use audits, camera systems, or sorting-line data.
Common contaminants include plastic bags, food scraps in recycling, tanglers like hoses and cords, textiles, and items that are recyclable but dirty. In organics, plastic, glass, and compostable-looking items that are not accepted are typical problems.
Facilities may set contamination limits in their contracts. Above the limit, the hauler might pay a surcharge, have a load rejected, or be sent to a landfill instead of the sorting line.
Why it matters for your business
Contamination is a cost that traces back to individual customers, even though the bill lands on you. The fix is nearly always communication and follow-up, not just fines.
A practical approach is to log cart tags and warnings in your CRM by address. A first offense gets a friendly note, a second gets a call or email, and repeat issues escalate under your service terms. That record protects you if a customer disputes a fee.
Marketing helps too. A short onboarding email, a “what goes where” page on your site, and periodic reminders cost little compared with processing penalties. For municipal and HOA contracts, showing how you track and reduce contamination strengthens a proposal.
Common questions
What is a good contamination rate?
It depends on the program, the processor, and local standards. Ask your facility what thresholds apply to your contract rather than assuming a number.
Example
If a 10-ton load is 20 percent non-accepted material as an illustration, two tons must be pulled out and disposed of, and the hauler may pay more for that load.