using a house brakcet for a tower no higher than that generally does not REQUIRE concrete, though it is recommended.
the bigger issue is that it is not naturally grounded. 3' deep in bare dirt does not in anyway provide an adequate ground. the tower ground MUST be bonded to the same ground as the home, as well as the "commercial grade surge protector". you can buy the best protectors on the market but if the ground system is not done properly they won't work properly. the purpose of grounding is to bring everything to exactly the same potential so that any surges flow around equipment and not thru it. if by chance your tower provides a better path to ground than other sources, then any surge will go thru the radio and other equipment connected to the tower to get there. seen it too many times, and will see it many more times before i am done with the radio business! you may get lucky and never have a problem, then again you can have an expensive strike.
if you want to do it right, you need a couple of 6-8' ground rods and bond them to teh tower as well as all the way back to your homes main electrical ground point. you don't use #6 for this, more like #2 or larger.
i put this out there just in case you don't know it.
i myself have had a 30' push up pole mounted to my house for 4 years now. the only ground it gets is the 12" of the pole below grade. so even us "pros" don't always follow our own advice!