A septic lagoon is a type of wastewater treatment system that consists of a large pond or basin into which sewage or effluent from the sewage system flows. The sewage and effluent are broken down by bacteria in the water, which is encouraged by environmental factors such as sunlight, warmth, and oxygen. The wind helps with the evaporation of the water and serves to get oxygen into the water. The resulting water is treated further, used in some way, or released into the surrounding environment without damaging it.

Septic lagoons are commonly used for onsite sewage treatment in low-population areas where soils are not suited for conventional absorption field systems. They are also used as part of all traditional and modern wastewater treatment plants, and they’re widely used as replacements for septic systems or informal cesspits that aren’t as tightly controlled.

For a septic lagoon to be able to break down the sewage or effluent properly and to be a healthy place, it must meet certain requirements:

• It must not be more than 1 meter deep.
• It must be surrounded by a high fence with a lockable gate to keep children and animals out.
• There must be an overflow situated directly opposite where the pipe carrying the sewage or effluent enters the lagoon.

New lagoon systems are required to be designed so disposal occurs by evaporation only. They should not rely on overflow, except during very heavy rainfall periods. However, where an existing lagoon system uses an overflow method, the overflow should not create a flooded or swampy area suitable for mosquito breeding, or where it may contaminate drinking water or the environment.

In summary, a septic lagoon is a type of wastewater treatment system that uses a large pond or basin to break down sewage or effluent from the sewage system. The water is treated further, used in some way, or released into the surrounding environment without damaging it. Septic lagoons are commonly used for onsite sewage treatment in low-population areas where soils are not suited for conventional absorption field systems.