I want to put the grate drain at the bottom of the steps where the blue square is located. The grate drain is 5 inches deep. My footer is 6 inches deep. I do not want to go under my footer. Can I knotch out a part of the footer (yellow circle) to connect to the drain tile? Or will that cause a structural issue. The reason is water runs down the step during heavy rainfall. I am using 4 inch perforated pvc.