The local health department may have septic tank placement requirements and a minimum setback distance from your foundation. Typically, it should be located on level ground so solids can settle in the tank. The location of the plumbing outlet usually dictates where the tank is located and depth of the tank to account for adequate slope on the inlet pipe. Septic tanks should be placed away from areas subject to flooding and surface water ponding. The tank should be properly vented. Avoid steep slopes and areas of dense tree roots or other obstructions. Also, place the septic tank where it is accessible for future inspections and pump outs.