I have a very similar profession, LeeG
And, no wonder, - a very similar bag!

However, mine is smaller and more casual looking. Thus it's always with me. That's because I'm wearing the Socttevest vest loaded with about 6 pounds of similar stuff in addition to the bag.

What I don't see in your great kit is a good heavy duty multitool (I EDC Juice too, but that's not enough quite often). The duct tape can be more versatile in signaling colors (red/orange). And for every IT pro I'd recommend to carry not simply a steel wire but an insulated one. Also I've found that all of the USB battery chargers are ridiculously underpowered (slow charging). A regular AC or car charger is much better. Maybe for your environment you should look at some good EDC water filters too. I like the really compact, and lightweight one from here: http://aquamira.com/consumer/aquamira-frontier-filter

Also I agree with Yuccahead - consider replacing Tums with a bit more expensive but much more compact, durable, faster acting, and longer lasting acid reducer (like Prilosec, Ranitidine, etc). Regarding the goggles. I'm carrying a pair of good swimming goggles (again - much more compact and versatile then anything else like that, plus added bonus of nutsness - as usual ).

By the way, is that Stainless Steel Nalgene Bottle fits inside the Cup?