First, they aren't projections, they are estimates. I wouldn't want you to think that these data were projecting something.
there's really no need to do that. Instead, try and figure out how the reintroduction rate would never be 100% of the water used.After you do, I'll explain to you how fracing works and how they filter the water used for a frac job and reintroduce it into the environment.
Obvioulsy, had I not been looking at net usage, the numbers for Oil would be much much higher than 2.1-5.4 gallons per gallon.