Mound septic systems are often the best solution if you have atypical soil conditions. For a septic system to work properly, it requires 36” of dry soil above the system to ensure bacteria, fungus, and other contaminants can be thoroughly filtered out. To determine the best placement of a new septic system, soil testing is performed. If the test returns a high water table or rocky soil, then an underground septic system will not work for your property. Instead, additional soil will be brought in and built up to form the three foot separation needed for the drainfield. When all is said and done, you will have a large mound in your yard that provides access to your septic system.