What must be done to keep squirrels and tree roots from distroying our septic tank & leechfield ?

What must be done to keep squirrels and tree roots from distroying our septic tank %26amp; leechfield ?


We live at 6000 feet above sea level. We don't want to kill either of them, just deter them... ?What must be done to keep squirrels and tree roots from distroying our septic tank %26amp; leechfield ?
There are several method of getting rid of squirrels at the link below:





http://www.pecanworld.com/SQUIRREL.htm





I don't know about tree roots. Farmers use a root pruner (Long knife attached to a tractor that cuts about 4' deep) around their fields to cut roots going into their fields and taking moisture from their crops. A trencher around the leechfield may work cutting the roots. Be careful and don't cut any laterals.