Help with Excel Formulas

I am creating a spreadsheet to help me quote electrical underground work. The spreadsheet allows me to enter information about all of the electrical conduit that will be in the ground (length, depth, pipe size, etc.), which is all important information and needed for accurate pricing. The problem I can't seem to figure out is that multiple rows can be in the same trench so I only need to use the longest run (all others will use same hole), but I need most of the other information in those rows. If anyone can help me with a formula that can look at matching values in "Trench Number" column, then take highest value in "Trench/Hole Length" column and delete or zero out any other values with same "Trench Number". If you can offer any help, I greatly appreciate it!

Area Trench Number Trench/Hole Length Depth-Inches

I have attached a sample spreadsheet for review.