Septic-system regulations vary widely from state to state. In most areas these regulations are set by the health department, so check with your agency to get specifics for your area. Almost all regulations are at a state level, with the EPA setting only a single standard concerning the distance between the septic system and a water-supply well. You will find most septic regulations have to do with distances and measurements.
As a general rule, the septic tank should be placed a minimum of 5 to 10 feet from the foundation of the structure. According to Missouri state regulations, a distance of 15 feet between foundation and septic tank is required if the home has a basement, according to the Inspectapedia website. The Uniform Plumbing Code recommends a standard distance of 10 feet.
Again, regulations vary, but in many areas a minimum tank size of 1,000 gallons is required in most residential applications. This requirement can change/increase if the home is especially large or contains more then three of four bedrooms.
Distance to Water Sources
EPA regulations require the septic tank be located a minimum of 50 feet away from any water-supply well. In many areas, this same minimum distance is required for streams, ponds, lakes or springs. Most septic tanks are buried 12 to 24 inches below the surface. General guidelines are tanks must be buried at least 6 inches below the surface.