I finally puzzled out what the usage units on my water bill are by digging through the city of Fernley's web site: kilogallons. The billing units are per 1,000 gallons of water, but the meters apparently don't read any more finely than that. Whether than means 1,001 gallons bills me as 2 kgal, I don't know. But now I do know that I have a baseline usage (with the now-repaired leak) of 4000-5000 gallons/month. We'll see next month what fixing the leaking pipe does to consumption. I can see that it won't actually affect the bill that much, as the variable amount per kgal is trivial compared to the base charge.