How do you properly vent a pressure relief valve on a water heater?

I'm buying a house and one of the things the appraiser said I need to do before they fund the house and I can close is to properly vent the pressure relief valve down to within 6" of the floor. The valve itself is on the top of the water heater and if it blew now it would spew at about my shoulder. Is it just a matter of running pipe down to the floor? Thank you for your help!!!!