Special waste is any solid waste or combination of solid wastes that due to its quantity, concentration, physical or chemical characteristics or, biological properties requires special handling and disposal. Examples of common special wastes include petroleum-contaminated soil, asbestos, stabilized grit & bar screenings, absorbent booms, and pads, liquids, pit sludge, bag house dusts, dried paint filters, bio solids, grease/scum waste, or any other hard-to-handle material that is not considered hazardous under RCRA. Following are four categories of special waste: 1) Commercial/Industrial Waste: This is non-hazardous industrial process waste, treated infectious waste and similar potentially harmful waste that requires special handling. Examples include: processed sludge, ash, filters, sandblast media and dusty wastes. Commercial/industrial waste must not contain "free" liquids and must be containerized if it can become airborne. 2) Liquid/Semi-solid waste: The Iowa Department of Natural Resources permits Waste Commission of Scott County to accept liquid and semi-solid waste. These wastes are mixed with absorbent materials to allow for beneficial use and proper disposal in the landfill. Examples include industrial liquids, cooling fluids, cutting oils, rinse water, latex paints and inks, food production waste, municipal waste, tank bottoms/sludges, and drilling waste. 3) Petroleum Contaminated Soils: These soils are non-hazardous and contaminated with petroleum products. This type of waste is treated by aeration and then used as a daily cover at the Scott Area Landfill. 4) Other Special Waste: These need special handling, such as spill cleanup materials, off-spec products, animal carcasses, drums and pressurized containers, fluorescent lights, and asbestos.