; (2) shall establish a process to waive specific covered towers from the marking requirements under this section as required under the rulemaking if the Administrator later determines such tower or towers do not pose a hazard to aviation safety; (3) shall consider, in establishing exclusions and granting waivers under this subsection, factors that may sufficiently mitigate risks to aviation safety, such as the length of time the tower has been in existence or alternative marking methods or technologies that maintains a tower’s level of conspicuousness to a degree which adequately maintains the safety of the airspace