Ask your propane company about permits as they'll usually handle this aspect of the installation and file all required paperwork. You can also contact the city code compliance office to ensure that all necessary gas permits and requirements are adhered to before the propane tank installation takes place.
Basically, a hernia is a defect in the abdominal wall that allows intestine to poke through. If the hernia becomes incarcerated (the intestine becomes strangled), then a blockage and rupture of the bowel can occur. This is life threateneing. Many people survive, but are permanently disfigured. A perforated bowel can mean months in the hospital, large portions of the bowel being removed, etc.
Most inguinal hernias happen because an opening in the muscle wall does not close as it should before birth. That leaves a weak area in the belly muscle. Pressure on that area can cause tissue to push through and bulge out. A hernia can occur soon after birth or much later in life. You are more likely to get a hernia if you are overweight or you do a lot of lifting, coughing, or straining. Hernias are more common in men.