I have a question for those who have hydroseeded for more than 1 year (because I'm in my 1st year with my unit). It's starting to get cool here, and I know my unit needs to be emptied so no seals break from freezing. My question is this: There's always about 20-30 gallons left in the bottom of the tank. How/where do you get rid of that so it can't sit in the tank/piping and freeze? Do you have a big hole at your location where you dump it? Do you drain it at the customer's house, giving them a blue street or driveway?