Which of the following is MOST affected by the presence of suspended solids in water?

The presence of suspended solids in water significantly impacts pathogen concentration because these solids can provide surfaces for pathogens to attach to and proliferate. Suspended solids can include a variety of materials, such as silt, organic matter, and waste particles, which can harbor bacteria, viruses, and other microorganisms. When these solids are present in higher concentrations, they can create an environment where pathogens can thrive, increasing their concentrations in the water.

In contrast, while suspended solids can also influence odor and color, their most critical effect is on the biological aspect of water quality, including pathogen levels. Odor and color primarily relate to the organic compounds and chemicals within the water, rather than directly being influenced by the physical presence of solids. Temperature, on the other hand, is more influenced by environmental factors than by suspended solids. Thus, the effect of suspended solids on pathogen concentration is the most notable aspect that highlights their impact on water quality.