Which of the following is NOT considered a containment technique?

Diking is a common technique used for the containment of spills, particularly in preventing hazardous materials from spreading into surrounding areas or water bodies. It involves creating a barrier, often made of earth or other materials, to contain liquids.

The correct answer highlights that diking is indeed considered a containment technique, while other methods such as covering, containment booms, and absorbent pads serve different but related roles in spill response and management. Covering can be used to shield spilled materials from environmental factors, containment booms are designed specifically to prevent the spread of liquids on water, and absorbent pads help to soak up spills. Each method is valuable in spill response scenarios, but the emphasis here is on understanding what constitutes containment techniques versus other forms of spill management.