A little difficult to find information about this sort of thing but once you've found it South Side Landfill is a great place to take your solid waste (rock, concrete, dirt, bricks, etc) as well as other refuse. It cost me $6 for a full pick-up load of waste from my back yard. The guys there are friendly and helpful. It's open 24 hours from Monday at 12pm till Saturday at 5pm so you should be able to fit in your dumping somewhere.