Land disposal by hazardous waste regulation includes:

The correct answer relates to "Waste pile" as a method of land disposal regulated under hazardous waste management. A waste pile refers to a management unit where hazardous waste is placed on the ground, usually in a contained manner, to prevent environmental contamination. This approach is important because waste piles must be managed in compliance with environmental regulations to minimize the risk of leakage, groundwater contamination, and air pollution.

In regulatory terms, the management of waste piles involves stringent controls to ensure that hazardous materials are not improperly released into the environment, taking into account factors such as their physical and chemical characteristics, potential for leaching, and proximity to sensitive areas.

Other disposal methods listed, such as incineration, sewer disposal, and fuel blending, may have their regulatory frameworks but do not specifically fall under the category of land disposal. Incineration is a thermal treatment process that destroys waste, while sewer disposal refers to discharging liquids into wastewater treatment systems, and fuel blending involves combining hazardous waste with other materials to be used as fuel. Each of these methods is governed by different regulatory processes and is distinct from the concept of land disposal.