If you're awake for around 16 hours, not sure why drinking an average of 500ml of fluids every 2 hours seems excessive to you. Or why drinking 1L of fluids every 2 hours (when your agenda for the day includes doing a 15 mile hike in hot weather) is considered a lot.
If what I've described above would make you go to the bathroom every 30 mins, perhaps see a doctor.