I'm located in Charleston, South Carolina and installed shallow well system. 3" casing at 22' and 1 1/4" suction pipe with foot valve at 20'. Water level in casing 9' level. Problem is pump and pressure great but after 1min. pump runs out of water and takes about 2min. to recover. Question: Should the casing have holes in it to allow water in from all levels? Soil sandy with clay mix.