Colchester: There are cold water fountains in the Library Reading Room, the Postgraduate Study Room and on the landings on Floors 2 and 4. 

Southend:  There is a water cooler on the 2nd floor of the Forum Library at the north end of the building, next to the coffee and food vending machines. 

Loughton; There are two water coolers, one in the SU Cafe next to the vending machines and one in Hatfields House. Ask the SU staff or at reception if you need help in finding them.