What is a common characteristic of Buried Sand Filters?

Buried sand filters are notable for their use of natural filtration processes that leverage the physical and biological properties of sand to treat wastewater. This mechanism essentially relies on the sand's ability to filter out particulates and allow for biological processes, such as the breakdown of organic materials, to occur.

The structure of buried sand filters typically consists of a bed of sand through which wastewater is passed, allowing for the trapping of contaminants as well as the promotion of microbial activity that contributes to effective wastewater treatment. This characteristic of utilizing natural filtration makes buried sand filters an environmentally friendly option for sewage treatment.

While it is true that some systems may require monitoring and maintenance, the defining trait of buried sand filters is primarily their reliance on natural filtration processes rather than any mechanical or constant intervention methods. Thus, the emphasis on natural filtration is what sets this option apart as the correct choice.