What are the environmental risks of improperly functioning septic systems?

Improperly functioning septic systems pose significant environmental risks primarily through the contamination of groundwater and surface water. When a septic system does not operate correctly, untreated or partially treated sewage can leach into the surrounding soil and ultimately reach water sources. This contamination can lead to serious public health concerns as pathogens, nutrients, and harmful chemicals enter the water supply, potentially causing illness in humans and animals.

The impact on groundwater is particularly concerning because many communities rely on wells for drinking water. If these wells become contaminated, it can lead to long-term health issues for the population. Additionally, surface water bodies, such as lakes and rivers, can also suffer from nutrient loading, leading to problems like algal blooms which deplete oxygen in water bodies and harm aquatic life.

The other options, while they may have some relevance to the overall impact of a malfunctioning septic system, do not address the primary and most pressing environmental risks associated with their failure. Overheating of the septic tank is not a typical concern in this context, and while increased maintenance costs and problems with local wildlife might result from septic failures, they do not capture the immediate and critical threat to water quality and public health that contamination presents.