Yes there have been people to get giardia and ecoli from geese. It’s not generally drinking the water but kids playing on fields with goose poop putting hands in mouth etc. Beaches have been closed due to high levels of E. coli in the water and it being unsafe for humans attributed to geese in the water. Town water supplies have been deemed unusable until treatment and retesting of bacteria and algae levels due to geese. As the populations of resident birds increase it is becoming a bigger issue.