Taste and odors in groundwater are commonly caused by which of the following?

In the context of groundwater taste and odor issues, disinfectant residuals can indeed be a contributing factor. When water is treated with disinfectants like chlorine or chloramines, they can leave a residual that may affect the taste and odor of the water, especially if the concentration is high or if the water is stagnant for some time. This can create an undesirable taste that consumers perceive as unpleasant.

While high mineral content, organic pollutants, and algal blooms also have the potential to cause taste and odor problems, they are related to different underlying causes or processes. High mineral content usually leads to hardness or specific mineral flavors such as salty or metallic tastes, rather than the chemical odors associated with disinfectants. Organic pollutants can lead to taste and odors, but they often come from external sources like agricultural runoff or wastewater, rather than being a direct result of water treatment processes. Algal blooms primarily affect surface water sources but can produce tastes and odors when they decay or when toxins are released.

Therefore, the primary association of taste and odors in groundwater with disinfectant residuals highlights the impact of treatment chemicals used in water disinfection, making it the best answer in this context.