Skyhawk 172/Cutlass 172
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (mon) 9; Air Traffic Control Time Certified In Pos 1 (yrs) 10
Confusion
Ground Event / Encounter Other / Unknown; Ground Incursion Runway
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Air Traffic Control Separated Traffic
Airport; Human Factors
The C172 pilot called local control ready for takeoff.  I told the pilot to hold short of Runway 28 because of traffic turning final.  The pilot read back the hold short instructions.  I noticed that it appeared the C-172 had crossed the hold short lines on taxiway Alpha (east end) and I told the inbound aircraft; on [short] final to go around; the aircraft on Alpha had crossed the hold short lines.  The pilot went around.  I then advised the C-172 pilot that he had crossed the hold short lines; and he apologized. I then cleared the C-172 for takeoff.  I then gave the C-172 pilot the Brasher Warning and asked him to call the tower when he landed at his destination.  He copied the tower phone number and said he would call.  I had no further contact with the pilot.I did not file this pilot deviation until local management advised that it could be considered a safety issue because of poor hold short markings.The airport authority should add additionally signage/markings/lights to the hold lines at each end of taxiway Alpha.  The hold lines at each end of taxiway Alpha are further back than the hold lines on all the other intersections for Runway 10/28; thus causing confusion for pilots.  Adding flashing lights to the current signs may be a possible solution.
A C-172 failed to stop prior to crossing the hold short line abnormally distant from Runway 28 on the parallel south taxiway. The reporter/Local Controller directed an aircraft on final to go-around and; after clearing the C-172 for takeoff advised its pilot of the Tower's phone number and requested a call upon landing. The Controller was never contacted.