If you are able to space the upper and lower strap/bracket assemblies about 2' to 3' apart, a 10' section of TV antenna mast or chain-link fence top rail can be safely held... Certainly with a compact antenna such as the ANT751R. In recent years, I've used top rail and 1" IMC conduit on antenna installations.
30' is larger than most masonry chimneys, but check
http://www.3starinc.com/chimney_mounts_1.html You may need to consider using two kits in tandem. If the chimney is a wood framed structure, consider using wall brackets.
If I was to go after the KC signals, I'd consider an Antennas Direct DB8E + Antennacraft Y10713 + preamp (Antennas Direct 'Juice' plus separate UHF/VHF combiner, or RCA TVPRAMP1R). The DB8E would face 90° per a real compass and the Y10713 would point at 42° (both are starting aim points, always fine tune for optimum overall reception reliability).
Both of the antennas just mentioned are rather directional... But they will have limited reception capability off the rear... Only after fine tuning the KC aim would you know for sure if the local signals would be reliably revived via the rear of the KC facing system.
If you need/want to, a premium solution would involve two independent antenna systems, the large combination aimed at KC, and separate ANT751R serving the Topeka market.
http://forum.tvfool.com/showthread.php?t=2882