On Saturday evening/night 6/22, from 4pm to 2am, I drank approx. 20 beers. I had an ETG urine test on Wednesday 6/26 at 11:30am. What are the chances I passed? I am 49, 5'9" 180 lbs. exercise a few days a week and drink a lot of water (about a gallon a day). Any insight would be helpful.

Chances are good that you passed but worrying about passing or failing would have been better to do before you started drinking... but you already knew that.