Which term best describes waste that has been treated to immobilize contaminants and reduce mobility?

• A. Alkali waste
• B. Wastes with inorganic chemicals
• C. Stabilized Waste
• D. Reactive chemical wastes

Answer: (C)

Immobilizing contaminants to keep them from spreading is achieved through stabilization, which locks hazardous constituents into a solid, less soluble form. When waste has undergone this treatment, it’s described as stabilized waste. This term directly communicates that an action was taken to reduce mobility and leachability, typically by mixing the waste with binding agents like cement or other materials to form a solid matrix. The other descriptions focus on what the waste contains or its reactivity, not on the treatment that reduces its mobility, so they don’t convey that immobilization step. In practice, stabilized waste is often evaluated for leach resistance using tests like TCLP to confirm the reduction in contaminant mobility.