Earth day commercial

I just saw a commercial for earth day which stated that if everyone in the U.S. shortened their morning shower by two minutes that we would save the amount of water in the great lakes every single day. That's great, that's a ton of water! Then I started thinking about it about a second after I heard it. There are roughly 310,000,000 people (rounded up about 4 million) in the U.S. (http://www.census.gov/main/www/popclock.html (http://www.census.gov/population/www/popclockus.html)) Lets assume that every single American showers every single day. The very young and the very old probably bathe every two or three days, but lets say they take a shower EVERY DAY. Given a GPM of 5 (which I believe is considerably above average, but I can do that math in my head) for two minutes is 3,100,000,000 gallons. According to http://www.wipapercouncil.org/documents/GL%20Compact%20Issue%20Paper.pdf, the great lakes contain roughly 5,900,000,000,000,000 gallons of water.
3,100,000,000
5,900,000,000,000,000
Something's wrong there, those numbers are 6 digits from even lining up! It would take 5,214 YEARS to save the amount of water in the great lakes. So maybe they meant to say everyone in the world, I'm sure they wouldn't just make up a number! There are 6,800,000,000 people in the world (http://www.census.gov/main/www/popclock.html), times 10 (for 5 GPM for 2 minutes) is 68,000,000,000. And since everyone in every third world country showers every day, we don't need to alter that number at all.
68,000,000,000
5,900,000,000,000,000
No, still not right. 241 years for the world to save the amount of water in the great lakes! These "greenies" must be counting on people to not think for themselves, a rediculous wish, becuase so many of them are such rational thinkers. Even though once the water comes out of the pipes it can never be reused and is sealed in a giant plastic container to prevent it from ever being released back into the groundwater (http://dictionary.reference.com/dic?q=sarcasm&search=search), that's a long time! I wonder what else they've lied about? And someone double check that math... I believe it to be correct, but that just seems like too long...

Something doesn't add up. The great lakes make up 22% of the world's fresh water. So if 2 minutes equals the same volume of the Great Lakes. That means if we all took a 9 minute shower, we would use all the World's fresh water in one morning.

Something doesn't add up. The great lakes make up 22% of the world's fresh water. So if 2 minutes equals the same volume of the Great Lakes. That means if we all took a 9 minute shower, we would use all the World's fresh water in one morning.

The great lakes do not "make up 22% of the world's fresh water" but they do make up 22% of the world's surface fresh water. Dang it, I hate when the water gets so fresh that you have to slap it silly.