But why would a business sign up?

"We are not recommending anybody stops selling water or affects their business," explained Ms Murdoch.

"But if people are coming in to fill up a water bottle they might buy something else."

And for the customer, she believes, the savings over a year of getting tap water in a reusable container rather than bottled could get close to £200.

"It is about behaviour change, it only takes a few months for people to get used to carrying it about," she said.

The Crichton Trust said it had been pleased to sign up to the scheme with various stations across the Crichton Estate in Neuro's Bar, Easterbrook Hall, Fresco's and in Grierson House.

"In doing so we are providing our customers, tenants, colleagues, students and visitors to the estate with access to free water on site without the need to regularly purchase plastic water bottles," a spokeswoman said.

It is also being widely promoted to participants in a park run on the estate.

'Great campaign'