Hillside foundation construction requires more than a knowledge of concrete construction. As a foundation contractor, I regularly take on the responsibilities of excavation and grading, trenching for footings, backfilling, and other earth work (see "A Good Excavator Is Hard to Find," page 28). Some of my most important work comes before and after I form and pour the concrete, including drilling piers, stabilizing the hillside, and providing adequate drainage. Hillside Stability One of the biggest problems with steep-site construction is that as you dig into a hillside, you remove material that holds the hill together, creating an unstable and potentially life-threatening situation. Unfortunately, hillside excavation is often left solely under the direction of the contractor, who may be working from plans that omit any mention of the problem.