The main environmental concern with improperly functioning septic systems is?

The main environmental concern with improperly functioning septic systems is groundwater contamination. Septic systems are designed to treat and dispose of household wastewater through a combination of physical, biological, and chemical processes. When these systems fail—due to issues such as leaks, blockages, or design flaws—they can allow untreated or partially treated sewage to seep into the surrounding soil.

This seepage can lead to harmful pathogens, nutrients like nitrogen and phosphorus, and other pollutants contaminating the groundwater, which is a critical source of drinking water for many communities. Contaminated groundwater poses serious public health risks, such as gastrointestinal illnesses and other infections, especially if people unknowingly consume this water.

Understanding the impact of septic systems on groundwater helps emphasize the need for proper system maintenance and oversight to protect public health and the environment.