OK, so you have an easement on his land. Have you talked to him?
You don’t want to have your insurance company pay for this. First, try and get him to fix it. Don’t contact his contractor. Let him contact the contractor. Don’t get in the middle.
Second, if he won’t fix it, have an attorney review your easement to make sure that he is responsible if he damages your pipes. If so, then have your attorney write a tough letter to him.
If it is not resolved, contact your insurance company and ask them.
If still not resolved, sue him if it is large enough to fool with.