Landfill days allow Thornton residents to bring items to the landfill that they may not be able to dispose of through their regular trash service. One load per household. Mattresses and box springs are subject to a fee of $30 each. Proof of residency is required. Non-hazardous debris only. Pickup, cars, and small single-axle trailer loads only (less than 5 yards). All loads must be covered. Commercial loads are subject to applicable fees. Freon charged appliances are not accepted. No liquids, electronics, tires, car batteries, medical waste, ammunition, fireworks, or fluorescent bulbs will be accepted. Safety vests must be worn at all times and are available at the landfill for $3.