Which type of water contamination is primarily tackled by sedimentation?

Sedimentation primarily addresses physical contamination, which involves particulate matter suspended in water. This can include dirt, sand, silt, and other solid materials that can be removed through the process of allowing the water to sit in a sedimentation basin. In this basin, gravity assists in settling these heavier particles to the bottom, effectively clarifying the water.

The sedimentation process is crucial in water treatment because it helps improve the quality of the water by reducing turbidity and removing solids that can harbor other contaminants, including microorganisms. While biological and chemical contaminants may also be present in water, sedimentation does not effectively eliminate these types of contaminants since they often require different treatment methods such as filtration, disinfection, or chemical treatment for removal. Additionally, thermal contamination, which relates to temperature, does not relate to particulate matter and is not managed through sedimentation processes. Thus, the focus of sedimentation on physical contaminants makes it the correct answer in this context.