I'm not sure where you are, but here in NC we have very hard clay and
my neighbor had a system installed using the "pipe puller" which is
trench less. I sat and watched the machine work and the first thing I
noticed it was not burring the pipe deep enough and he will have
problems aerating the lawn. This fall he aerated and seeded. When he
turned on water it was leaking from everywhere. Also, even if you hit
the pipe and did not brake it right away it will put micro cracks in
the PVC and over time it will crack.

Contractors love to use it because it saves them time and money. Pay
the extra bucks to have it trenched and don't worry about the extra
mess you will never have to worry about hitting pipes.

Or install it yourself, If you think you might want to I can shoot you
a web site that is the best on the net for do it yourselfers. Do not
use the free design offers from the manufactures or you will be sorry!

I also have some other tips for you if you choose to have a contractor
install your system, that will have you some major bucks down the
road.