[600MRG] Distance from powerline question

[Andy - KU4XR]

Greetings all :

In all seriousness on this matter.. I did a lot of net searching to no avail.. My question is :
" How far out from a standard service line ( 4 to 13 KV ) does the EMF field extend ?? "
With my long term thinking of " more is better " , I recently added a meager 40 feet length
to my LF antenna.. This however put the end about 10 feet from the powerline on the far side
of my property.. The end is almost at a 90 degree angle to the line, and I also have 20 feet 
of that hanging vertically.. Powerline buzz is not my issue, it is as if the entire spectrum 
has deafened ..  I plan to shorten the length by at least 20 feet, which will put the end of the 
antenna 30 feet from the powerline.. 30 feet is the only distance reference I could find
after hours of searching.. Of course the common consensus was " The farther the better ",
but this was a safety, and exposure reference.. Is there a Radio Antenna recommended
distance, or does the field vary depending on the load on the line at any given moment ??

Thanks for your time, and have a great day :

Andy - KU4XR