Construction workers removed a deseased tree and its roots outside of my property a year ago. A new tree was planted to compensate nearby but now the ground is sinking where the old tree used to be! When the construction workers removed the roots what should they have done to try and prevent the ground collapsing in this way?

Reply to post by t motgan, on July 15, 2002 at 11:28:14:

The reason for the settling is that the roots are organic matter and are decaying. As the wood rots, it takes up less room. Grinding of the stump (if it was ground out) still leaves some roots in the ground. Only the main part of the stump is ground up. Chasing all the large roots would tear up the lawn, make a bigger mess, cost more, and still would probably not get all the roots out. The soil that is left behind, mixed with the rest, will also settle over time, as it is much looser than the compacted origianl soil.

If the contractor left the stump grindings behind, they will also decay and settle. This is often the biggest problem. If the grindings were left, you can still remove some of the material and replace it with a good soil, lightly tamped into place.

The good news is that the settling should be done after a year or two, and any additional soil won't settle as much. You can just level the area with some fresh so and go on from there.

See the tech report on stump grinding at the link below, and select "Stump Removal" from the menu.