"1550 So. Lumber St. Water Quality Control Station". Waste from the train cannot just be dumped into the city sewer system. It first has to be treated before the city will allow it to be dumped into the sewers. That is what is done in this building.
The photos in this slide show were taken in the mid-1990's by Steve Grande on his Amtrak travels throughout the nation. The size of the photos is purposely smaller as disk space was expensive and download speeds were slower at that time.