When the ground below a septic system is either strong rock or near groundwater, a mound system works better than a standard septic leach area. Inside this type of system, a mound of ground is constructed over the all-natural outermost layer of the soil. Effluent is pumped through the pipes within the mound. Some of the effluent drains downward; some evaporates. Though the mound is an efficient way of disposing of household sewage, it has a tendency to be awful from a landscaping point of view. With a little work, however, it is possible to camouflage a septic mound.
Taper the borders of the mound by bringing in additional soil and piling around the borders of the mound. You can bend these berms or pluck them so that they blend in better with your lawn. Topsoil on the borders of the mound can stretch out as far as you want, but topsoil on the mound itself must be 6 to 16 inches deep.
Cover the mound and the next berm with bud or a low, dense ground cover plant. Make sure that the whole mound is covered and there is not any bare ground.
Plant shrubs or perennial plants around the berms around the mound or along the borders where the berms match the flat portion of your lawn. Avoid planting shrubs or anything with heavy roots on the mound itself.