What are potential consequences of improperly installed septic systems?

The choice of groundwater contamination as the correct answer highlights a significant concern associated with improperly installed septic systems. When a septic system is not correctly designed, installed, or maintained, it can lead to the failure of the system. This failure often results in untreated or partially treated sewage leaking into the surrounding soil and subsequently entering the groundwater. Contaminated groundwater poses serious health risks to humans and the environment, as it can carry pathogens, nutrients, and other harmful substances.

Additionally, groundwater contamination can affect drinking water sources, leading to increased health risks for those relying on well water. Consequently, proper installation and maintenance of septic systems are critical not only to ensure the safety and health of individuals but also to protect the surrounding ecosystem and water resources.

In contrast, the other options—such as increased property value, improved soil quality, and enhanced drainage—do not typically arise from an improperly installed septic system. Instead, these outcomes are more aligned with well-designed and functioning systems, which can positively impact property value and soil health while providing proper drainage.