Land disposal unit

A land disposal unit, or LDU, is a site in which hazardous waste is remedied through natural and man-made processes. "Land disposal" of hazardous waste is defined in the U.S. Resource Conservation and Recovery Act (RCRA). Types of LDUs for hazardous waste disposal:
 * Landfill
 * Surface impoundment
 * Waste pile
 * Land treatment unit
 * Injection well
 * Salt dome formation
 * Salt bed formation
 * Mine
 * Cave.