Final answer:
Always keep the blade of the shovel perpendicular to the side of the utility when digging around underground utilities by hand.
Step-by-step explanation:
When digging around underground utilities by hand with a shovel, always keep the blade of the shovel perpendicular to the side of the utility. This means you should have the blade of the shovel at a right angle to the utility, creating a T-shape. This is important to prevent accidental damage to the utility lines. By keeping the blade perpendicular, you minimize the risk of hitting the utility and causing any disruptions or accidents.