What is a percolation pit?

A Percolation Pit, also known as a Soakaway or a Leach Pit, is an underground structure designed to absorb and disperse wastewater into the ground. It is commonly used in areas where there is no access to a municipal sewage system or when installing a conventional septic tank is not feasible. Percolation pits are mainly employed in rural areas, remote locations, or for smaller-scale wastewater management.

Here's how a percolation pit typically works:

Construction:

- A pit is excavated in the ground. The size of the pit depends on factors like the volume of wastewater to be disposed of and the soil's infiltration rate.

- The bottom and sides of the pit are lined with coarse gravel, stones, or other permeable materials to create a drainage layer.

Wastewater Collection:

- Wastewater from a dwelling or building is collected and directed into the percolation pit. This can be achieved through pipes or channels.

Infiltration:

- As wastewater enters the percolation pit, it starts to seep through the gravel or stones at the bottom and sides of the pit. The wastewater gradually infiltrates into the surrounding soil.

Filtration and Purification:

- As the wastewater seeps through the soil, it undergoes filtration and purification. The soil acts as a natural filter, removing contaminants and pollutants from the wastewater. Beneficial microorganisms in the soil also help in breaking down organic matter and further treating the wastewater.

Dispersal:

- The purified water disperses into the soil and eventually recharges the groundwater. The dispersal of water helps prevent waterlogging and promotes groundwater recharge, benefiting the ecosystem and local water resources.

Overflow and Maintenance:

- Percolation pits require periodic maintenance to function efficiently. If the pit becomes clogged or filled with sediment, its infiltration capacity may decrease. In such cases, the pit may need to be cleaned or replaced. Some percolation pits may also have an overflow mechanism to redirect excess wastewater in case the pit becomes overwhelmed.

Percolation pits are an environmentally friendly and cost-effective solution for wastewater management in areas with suitable soil conditions and low wastewater volumes. They promote the reuse and conservation of water while protecting the environment and groundwater quality.