What design is recommended for separate laundry and gray water beds on high clay sites?

The recommendation for not allowing primary system size reduction on high clay sites is grounded in the unique challenges that clay soils present in terms of drainage and absorption. Clay tends to have very low permeability, meaning that it does not allow water to pass through it easily. This can lead to problems such as ponding, clogging of the system, and in some cases, can even cause the system to fail if not designed or sized appropriately.

When dealing with separate laundry and gray water beds, it is crucial to maintain the full size of the primary system because a reduction could lead to inadequate absorption capacity. If the system is too small for the volume of wastewater it is designed to handle, it could result in surface water runoff or saturation, creating environmental hazards and health risks. Therefore, while some systems may allow for size reductions under certain conditions, high clay soils necessitate maintaining the original size to ensure proper function and prevent failure.

In contrast, system size reduction is typically acceptable in soils with better drainage characteristics (like sandy soils) where excess water can be absorbed effectively without complications. However, with clay, the design must remain intact to manage the functional output of the septic system.