Coerco septic tanks aren't trafficable, and although Coerco leach drains can be configured to be, the Department of Health doesn't allow for leach drains to be installed in trafficable areas.
Coerco poly septic tanks aren’t trafficable. However, an engineered cover above the buried tank and an access opening can be installed to ensure safety and ease of maintenance/inspection.
E.g. An engineered concrete slab designed to cover a poly septic tank.
If your cover must be subjected to wheeled traffic, it must first be approved by the Executive Director, Public health.
On the other hand, Coerco leach drains can be configured to be trafficable by reinforcing them with more internal panels.
On the whole, however, the Department of Health doesn't allow for leach drains to be installed in trafficable areas. This is to prevent vehicles from damaging pipes, compacting the soil and compromising evaporation. Oxygen also helps the soil around the drain/leach field to break down waste, but concrete or asphalt would only serve to impede oxygen and further reduce waste breakdown by microorganisms in the soil.