What are your water and sewer rates? I have a wash in one town that recently had an increase. The town has decided to use a new method of calculating sewer rates based off a formula they found published somewhere.
They say that the average carwash bay uses 3.1 times as much water as a typical household. National averages for monthly water use by a house is a little over 10,000 gallons each. This city does not water meter households but does all commercial business. They do not break it out by SS bay, automatic bay or other means just 3.1 times the number of bays. I have 3 SS bays and 2 auto bays so my sewer charge is 16 times the typical house. A household is charged $42 per month. So my bill for sewer is always $672 no matter how much water I use. The first month I got the bill I used 66,000 gallons of water but essentially had to pay for 160,000 gallons of sewage.