Which of the following water types typically requires the highest filtration effort?

The choice indicating that cloudy water with high suspended solids typically requires the highest filtration effort is correct due to the nature of suspended solids. When water contains a high concentration of suspended solids, it can include particles such as dirt, silt, organic matter, and other debris that cloud the water. These solids can significantly impede the flow of water and reduce the effectiveness of any existing filtration systems.

Filtration processes need to be more robust and possibly prolonged to remove these suspended solids effectively. This often necessitates using advanced filtration methods, like sedimentation followed by filtration or multi-stage filtration systems, to ensure that the water meets quality standards. The presence of these high levels of suspended solids can also lead to frequent clogging of filters, further emphasizing the need for a high filtration effort.

In contrast, water with low dissolved solids or filtered water would generally pose fewer challenges to filtration. High pH water and its implications may influence other treatment processes but do not inherently increase the complexity of the filtration process compared to water with high levels of suspended solids.