I have seen your posts on this subject on High Def Forum, and rest assured that if your tower is in concrete in the ground, that it IS grounded. If you are concerned about a shunt of static electricity going to your TV set, then you should ground the coaxial cable at the point where it enters the building. You accomplish this by buying an inexpensive grounding clamp, which is inserted in the coax line at the point of entry to the house. and is then connected via either aluminum or copper grounding cable to a 4' grounding rod driven into the soil. The installation manual that I have linked to you will give you good directions.
http://manuals.solidsignal.com/AntInstallGuide.pdf
When you are ready to discuss how to take best advantage of that good old 40' tower, i will be happy to make some suggestions. Using a Phillips MANT 940 on that tower is like running the Indianapolis 500 on bald retreads.