I have a moist area near my house and septic system and want to plant a tree that will not affect foundation nor go down to septic system. What, if any, types of dwarf trees should I be looking into?
Use caution when planting near and around your septic system.
As a homeowner with septic tanks I can tell you that the recommendation is no trees, not even dwarf varieties.
Shrubs and perennials can be utilized and are much safer.
Here are some links for you.