How much separation is required between trenches of a standard drainfield installation?

In a standard drainfield installation, a separation of 3 feet between trenches is essential to ensure proper effluent distribution and avoid oversaturation of the soil. This distance allows sufficient space for the effluent from each trench to infiltrate into the soil and be adequately treated before it reaches the water table. The 3-foot separation helps minimize the risk of cross-contamination between the trenches and also aids in maintaining efficient treatment of the wastewater.

Choosing a separation distance lower than 3 feet could lead to insufficient treatment and potential hydraulic overload of the soil, while a greater separation may not be necessary in most standard installations and can lead to inefficiencies in land use. Therefore, the 3-foot separation is a carefully established standard that balances effective treatment with practical installation considerations.