Normal we operate with a 5 man pipe crew. But we are bidding on an upcoming sanitary sewer job that will get premium aggregate and it's 12' deep on average. Should I have an extra operator and excavator/ho-pac with the crew at all times to assure backfill is handled properly? At what depth/condition is an extra operator typically needed? What would be an ideal crew makeup (laborers, operators) and their common tasks?