There are 3 traps that kill zombies located throughout the map:
• Electric Floor, Location - Spawn Room (Next to stairs)
• Sniper Towers, Location - Atlas Command (In room with 3D Printer)
• Aligators, Location - Sewers (Left under the bridge as you enter from Atlas area)
My personal favourite is the Electric Floor as it is right at the start so can be accessed quickly. Simply Set of the trap once the round starts and head up the stairs behind you then jump around the room until the trap has reset and us it again. This achievement doesn't need to be done in one play through however is easy to do solo in one session.