What is the primary function of a greywater disposal field?

The primary function of a greywater disposal field is to filter greywater using stone and gravel, making this the correct answer. Greywater, which is wastewater from domestic activities such as laundry, dishwashing, and bathing, is typically less contaminated than blackwater (which comes from toilets). The disposal field is designed to ensure that this wastewater is treated to some extent as it passes through various layers of stone and gravel, which help remove impurities and allow for the percolation of water into the soil.

The filtering process is essential for reducing pollutants and pathogens in the greywater, making it safer for eventual discharge into the environment or for potential reuse such as irrigation. By allowing the greywater to flow through this media, the field provides biological filtration, which further breaks down organic materials.

While irrigating plants using greywater or storing it before irrigation are potential functions of greywater systems in general, these processes do not specifically define the primary role of a disposal field itself. Creating a ponding area for greywater is not typically a function of a disposal field since ponding can lead to water stagnation and may create health risks. The focus of a greywater disposal field is on effective filtering to protect both public health and the environment.