The hand pump that Abul Kalam uses to fetch drinking water for his family of eight is good for about 20 minutes' supply.
But after that, Rohingya refugees in the sprawling Balukhali camp in southern Bangladesh must wait for its underground reservoir to refill.
"Our three blocks [about 300 families] … completely depend on this well," he says.
Another nearby has dried up already.
"This will stop functioning in the next 15 days, or a month," the 45-year-old says, gesturing at the now-dry pump he'd just been using.
"I have feeling that we are going to face an acute shortage of water."
There are approximately 4,600 of these pumps in the various camps, making them the primary source of water for the majority of refugees.
But according to United Nation figures, a third of them are either dry or pump contaminated water.
"This is a city, living off shallow hand pumps that are drying up every day," says Australian Red Cross water engineer Mark Handby.
Mr Handby, who is from western Victoria, shows the ABC one open reservoir in the Balukhali camp, near where Abul Kalam draws his water.
"This has now dropped to a point, and become contaminated to a point, that currently we're not able to use it," Mr Handby he says as he points out algal growth.
"It was our urgent option, and now it's gone."
Race against time to secure water supply
Mr Handby says it's now a race against time to drill deep, expensive bores in an effort to secure supply.
"Potentially down to 300 metres," he says. "To ensure that we get enough water, and its safe to drink."
The urgency, he says, can't be understated.
The only alternatives are trying to truck in water for hundreds of thousands of people, or moving the refugees.
Although the camps' expansion was ad hoc, the issue is not a lack of planning. The water table simply cannot satisfy the needs of the people who now depend on it.
Indeed Balukhali, one of of the biggest camps, means 'empty sands' in Bengali.
Taking into account earlier arrivals, 830,000 Rohingya are now camped there and in other settlements carved into the surrounding hills and paddies.
Bangladesh has long said it cannot sustain the refugees indefinitely, but that statement — meant as a plea for international help — is now a frighteningly real reflection of their impact.
Overcrowding is a 'huge problem'
Phoebe Goodwin, a Sydney architect now working as a planner for the UNHCR, said the biggest problem was simply "space".
"As you can see its almost a sea of roofs in front of us," she said from a hill overlooking the Kutupalong camp makeshift extension.
"So overcrowding is a huge problem."
Ms Goodwin is planning new extensions to the camps, and key amongst the tasks is trying to locate latrines away from pump wells so sewage does not contaminate the scarce groundwater.
Longer term, there are plans for rubbish incinerators, waste treatment and possibly a solar farm.
Aid agencies working in the camps say those services are essential to prevent disease and provide the residents a dignified existence.
However, Bangladesh has been reluctant to approve some bigger projects, for fear they will encourage the refugees to stay.
For most of the Rohingya refugees the ABC met the prospect of eventual return is a distant consideration, if that.
Their energy is focussed simply on getting by, on providing their families with the very basics of life.
Staring at the semi-functioning pump he'd just been using, Mr Kalam's request is simple, if problematic.
"We need more," he says.
"If this one stops functioning, then we are going to face severe water crisis."
Find out how you can donate to the Myanmar-Bangladesh Appeal.