Solid Waste Exclusions [40 CFR 261.4(a)]
The process of determining which wastes are hazardous waste at 40 CFR 262.11 requires you to first determine if you have a solid waste as defined at 40 CFR 261.2. Then, you must determine if your solid waste is excluded from regulation at 40 CFR 261.4.
Many people are confused by the apparent contradictions in the solid waste definitions and their exclusions. For example, 40 CFR 261.4(a)(7) states that spent sulfuric acid being reclaimed to make virgin sulfuric acid is not a solid waste. This directly contradicts the “recycling table” at 261.2, where the “reclaiming” column contains an asterisk in the “spent material” row, indicating that it is a solid waste when recycling in that manner.
Keep in mind that everything identified at 40 CFR 261.4(a) does meet the definition of “solid waste” at 261.2. If it did not, there would be no need to exclude any specific wastes from regulation. Other examples of materials that meet the definition of solid waste, but are not regulated as a solid waste due to 261.4(a) include:
- Domestic sewage
- Industrial wastewater discharges
- Irrigation return flows
- Certain nuclear materials regulated by the Atomic Energy Act
- In-situ mining materials
- Pulping liquors that are reclaimed and reused in the pulping process
Many states adopt all of the exclusions at 261.4(a) by reference. Some, such as California and Texas, adopt only some of them. You are allowed to take advantage of these exclusions only if your state has adopted them.