What problems can arise from malfunctioning septic tank systems?

Malfunctioning septic tank systems can lead to significant environmental and public health issues, making the option of surface water pollution, groundwater contamination, and standing sewage in neighborhoods the correct choice. When a septic system fails, untreated sewage may leach into the surrounding soil, impacting local waterways and potentially reaching groundwater sources. This contamination can lead to harmful effects on aquatic ecosystems and pose serious health risks to communities due to the pathogens and pollutants present in untreated wastewater.

Conversely, increased oxygen levels in water typically result from healthy ecosystems and are not a direct consequence of septic system malfunctions. Improved soil fertility and enhanced water filtration would suggest more beneficial outcomes, which do not align with the repercussions of a failing septic system, as these situations instead lead to detrimental impacts on the environment and overall public health.