Squiddly - Google call before you dig - CBYD - looks like the number is 811. They will come out & tel you what is underground. Probably tell you other rules, too. att can disturb anything you do there if they need to bury facilities.
Have a hunch you can't do anything in that easement if it doesn't have an end date. Once there is an easement, it's there forever.
Here in MI the easements are spelled out in MI law and defined in size and location. When no alley, there is a 6' easement between the back yards of all the houses on the adjoining streets. That's where the poles w/electric. ATT and cable lines are.
ATT put a VRAD next to a back set garage in that 6' easement, about 3' from the sidewalk.
Please NO SD stretch-o-vision or 480 SD HD Channels Need Help? 1-800-288-2020, After he gets acct info, press # a bunch of times, get a menu from Mr. Voice recognition Your Results May Vary, In My Humble Opinion I Call It Like I See It, Simply a U-verse user, nothing more