Interesting document on parent company Iowa Pacific's website. It lists subsidiary Chicago Terminal customers and the rates that are charged to switch them. My guess is that based on an estimated 500 carloads per year of mostly scrap steel that Chicago Terminal's downtown operation grosses about $135,000.
The document lists Peerless which is gone of course but it also shows Waste Management on Goose Island as a customer. The track that went to Waste Management has been out of service and taken up for the most part for decades. I never saw a freight car spotted at Waste Management at any time during the Soo Line era from the mid-1980s on though it is possible I could have missed one.