1) Consult with a Lawyer that knows Ohio law.
2) Mark the  tile lines, tile outlets, water lines, gas lines, electric lines, culverts, ect. that you have installed or had installed in the areas that Spectrum wants to bury their line. Calling 811 is not going to locate these lines. Talk with the contractor that is burying the line. You want the involved private lines located, specifically Id ask they be DAYLIGHTED (EXPOSED USING A VAC TRUCK.) This will be a 3-4 inch holes sucked out with a vacuum,down to the involved item.  The guy following the boring head and measuring depth can SEE the boring machine did not interfere with your utilities. You will have to mark where they are for a contractor to find them.
3) Be prepared, if necessary, to shut down the combine and be on site when the vac truck shows up. The better you have them marked, the shorter shut down time will be. This should be HOURS, not DAYS.
Remember the 7 P's. PROPER PRIOR PLANNING PREVENTS P*SS POOR PERFORMANCE.
4) If you know the depth of your lines, say tile at 3 feet, you could say "From here to here, go 6 feet deep.