Hello, I live in Michigan.I drove out the woodchucks last year filled in their holes,but they came back and dug a tunnel under my driveway.I am looking for ways to shoot sand up inside to seal off hole.I have priced grout pumps and foam systems,Im not going to drill holes in the top and hire a mudjacking co. I am looking for ways to shoot sand way up inside to fill hole,then I'll make sure this doesnt happen again.They never came around drive before,and I never thought of it until they did. I thought a sandblaster with as big a nozzle I can get. Any suggestion? Thank you for your help!