While little is known about this area of study, student John Bevan says that its popularity comes down to the intrigue.

“It’s not clear-cut like steel or cement,” he said.

“Sometimes the data you get back won’t add up and you have to make your own interpretation of it.”

Professor Ian Acworth said it was originally thought

there were few fractures in

the rock on site, limiting the flow of water to the alluvial channel.

Studies have since revealed that this site is more permeable, and there is more water underground than previously assumed.

Students also ran tests to ascertain the age of the groundwater.

On site they checked oxygen, temperature and ph.

They studied the water’s ability to buffer acidity to ascertain how evolved the water was in terms of its reaction with the rock.

They will also check samples for tritium, a radioactive tracer with a half-life of 12.3 years.

“We know very little about hydraulic processes in rock,” Dr Martin Andersen said.

“If we find out how permeable it is, we can then find out if it is old water or fast flowing young water –these are all ways of giving us hints and clues.”

“It’s important because that will tell us how renewable it is.

“If it is very old it teaches us it takes a long time to recharge.”