Canberra Hospital sends 360,000 plastic water bottles to recycling plants each year because the Government's health policy is to use them over reusable jugs.
A spokeswoman initially said the hospital lacked the proper equipment to make reusable jugs safe, in response to questions sent by the ABC.
"The reason for this is that providing water to patients with water jugs requires specific sanitisation equipment as well as strict management of collection and refilling to minimise possible cross-contamination and infection-related risks," she said.
"Plans are currently progressing for new dishwashing facilities at Canberra Hospital, with this equipment upgrade, ACT Health is planning to reconsider the most effective way to provide patients with water in the future."
However, when the ABC later asked how the hospital could ensure hygiene standards with plates and other items at meal time without the correct equipment to sanitise water jugs, the spokeswoman said the dishwasher was equipped to clean and sanitise all items provided to patients.
"It is also important to clarify that it is equipped and able to sanitise water jugs," the written response read.
"However, ACT Health's current policy is to use bottled water."
The ACT's health directorate confirmed the decision to distribute bottled water to patients at least three times per day, at meal times and upon request, was made in 2000.
The Government said it was the most efficient way to supply water to patients while minimising the risk of contamination and infection.
While water bubblers and refill stations are available in parts of the hospital, the Government did not provide information on how frequently they were used.
The Government stressed efforts were made to ensure the bottles were recycled, and that the University of Canberra Public Hospital, which is currently being constructed, would use jugs to serve water.
'Keen to keep pressure on': Rattenbury
ACT Greens Leader Shane Rattenbury said he was "keen to keep the pressure" on Canberra Hospital to ensure they eliminate the use of plastic bottles where possible.
"Canberra Hospital has been restrained here," Mr Rattenbury said.
"Certainly the fact the new approach is taking place at the new hospital demonstrates people have been thinking about these things."
Mr Rattenbury agreed that the Government should set an example in this area and said it was trying to reduce plastic use across the city.
"I'm certainly keen to see bubblers rolled across the city," he said.
"They're the kind of places where it's really easy savings where it comes to plastic."
