Alright, I finally landed a new summer job at a private surveying/consulting/civil engineering firm. My time is going to be split pretty much 50/50 between the office and paperwork and field work, surveying, and staking. One of the things I was told that caught my attention is that I might be dealing with trenches once in a while. I know Paul has quite a bit of experience with this but he's on a cross country road trip at the moment. What are some things I should look for or guidelines I should use to know whether or not it's safe to go down into a trench?