have to give a bid on a 2000 sq ft house tomorrow afternoon. Problem is is that i dont have a tank and therefore will have to use his water. The person has well water and i have a 3500 psi 6-8 gpm pressure washer. About how many gallons of water is this gonna use? the problem im afraid of is running the well dry? Any others have jobs where the us of the peoples well water was used? Can this job be done safely with out running well dry? Or should i just pass on this one and tell them they will probably need to find a washer who has a tank?