Which soil group is classified as provisionally suitable based on clayey texture?

Soil Group IV is classified as provisionally suitable based on its clayey texture. This classification indicates that while the soil has a high clay content, which can affect drainage and permeability, it still has some potential for septic system installation under specific conditions.

Clayey soils can retain water, which may lead to slower percolation rates. However, they can also provide a stable base for systems designed to handle such conditions, especially with proper design and implementation. The provisionally suitable designation suggests that with the right management practices, such as constructing an appropriately sized system or incorporating drainage enhancements, these soils can function adequately for septic purposes.

The other soil groups would either be unsuitable or more limited in their capacity for septic installation due to their characteristics, making Soil Group IV the correct choice in this context.