“How were the separation distances from the bottom of the sewage treatment trench or bed to limiting soil layer determined?” This is a question I receive often, and one primary reason why is the variation in state and local code requirements for separation distances.
In Minnesota, where I worked for over 30 years, there is a 3-foot separation requirement; and in Arizona, where I also worked for over two decades, there is a 4- to 5-foot requirement, depending on conditions. I have talked with many of you who see that type of variation between counties in your states.
A recent
