How to kill a 15 meters high tree ?

[Bill Roberts]

Best thing you can do is get a tree surgeon to cut it down in pieces 
and then poison the whole root system. It will die off fairly quickly 
once it's been poisoned.  

You will not be able to partially kill the roots near your pipes, 
they'll just keep coming back.  Poplars are well-known for damaging 
water pipes, so it your already worried about it get it felled.

Don't wait another 5 years so it's grown another 20 feet, it'll cost 
you more to remove it then.

Bill, Edinburgh