What amount water would be considerred too much to drink a day?

Depends: How much water is too much depends on your age, and activity, environment, overall health. People with congestive heart failure or kidney disease can get in trouble if they drink water in amounts that normal people can handle safely. Here's a good discussion on "water intoxication." https://en.wikipedia.org/wiki/Water_intoxication Here's another easier article: https://tinyurl.com/y7wd2frv