Both Apollo and the Shuttle launched from KSC complex 39, and used liquid oxygen and liquid hydrogen as propellants. These cryogenic liquids were held in storage tanks near the perimeter of each launch pad (at the 11 o'clock and 3 o'clock positions in the picture below), until they were pumped into the spacecrafts prior to launch.
The thermal insulation of a storage tank is never perfect, and the cryogenic contents will slowly vaporize. How were the boiled-off gases treated? Were they simply released to the air, were they collected for further storage, or was there some system to burn these gases?