Pine tree roots
I have 15 beautiful mature pine trees (probalbly 75+ ft tall). I had to cut one down and have it's stump ground to 1 ft below ground level because it's roots were discovered to be attacking my septic tank. Now I've been told by the septic tank clean-out company that the tree's roots will continue to grow underground even though the pine tree has been cut down and the stump ground out. I've done "Google" searches but cannot collaborate this info. Any opinions or arboristis out there with knowledge of this problem?