Question
We live in a 70's house with 4 liquid amber trees on one side and another one on another side, downhill but near our leach field.  The trees are planted approximately 12' from the foundation and as yet, we have had no noticeable problems from them.  They are approximately 45 feet tall, but I do not know how old they are.  I have been reading horror stories about them breaking up foundations, etc.  Since I am relandscaping the yard, should I have them removed?  I live in northern California.
I would appreciate any help or suggestions.

Answer
Yes that is too close to the foundation and over time there maybe damage to the foundation from the root system. I would consider replacing the trees. If you do treat the freshly cut stumps with Roundup to kill any sprouts from the root system. Roundup is a herbicide that will be taken up by the stump and transported to the root system killing the roots. If you do not do this you may get sprout from the roots coming up in your new yard. I would check with your local tree nursery and ask about a tree suited for your yard conditions and your desires in a tree (fall color, flowering).