Many variables. You need to understand the amount of water used per wash package. Our Washworld Razor uses about 70gals per package (each of 3 options), 35 for our basic package. Self service should use about 3-4 gallons per minute. For RO you use 2 gallons to make one gallon of Spot free but we reclaim the discarded water from RO process and use it on the touch free machines. For 190K gallons I would expect you to have washed 2000 plus cars with IBAs. Maybe the invoice was for multiple months?we have two touch free and three SS, and i don't feel I'm washing a respectable amount of cars is my concern. I'm worried there is an issue with my RO. if the membranes are bad would a higher percentage go to waste? It looks like we washed 1050 cars that month which is only 35 per day.