I understand that it makes sense to outsource this work, rather than doing it in-house. I wasn't suggesting the district do it in-house. What I don't understan

I understand that it makes sense to outsource this work, rather than doing it in-house. I wasn't suggesting the district do it in-house. What I don't understand is: why is the market-clearing price for this service positive, instead of negative? I wonder how much net profit the recyclers make, per ton.