What is a common visual cue that suggests issues with a septic system's drain field?

A common visual cue that indicates potential issues with a septic system's drain field is the presence of dense vegetation spread. This condition typically arises when the soil receives excess nutrients from the septic system's effluent, which can enhance plant growth in those areas. A thriving patch of vegetation suggests that the drain field is functioning improperly, potentially causing an overflow or system saturation. This excess nutrient accumulation can indicate that the system is not adequately dispersing wastewater, which is essential for its functioning.

In contrast, the other options, such as bare patches in grass or minimal water presence, often indicate other potential issues but do not specifically signify active problems related to nutrient leaching or saturation like dense vegetation would. Even soil moisture may suggest a balanced system but does not directly point to problems the way abundant plant growth does. This makes dense vegetation an effective warning sign for septic system owners and installers.