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'

The project has also received Scottish government support, fuelling hopes it can spread much further.

Environment Secretary Roseanna Cunningham said: "This is a great campaign and I encourage everyone to make the switch to reusable bottles whenever possible.

"We all have a role to play in changing Scotland's throwaway culture and we all stand to benefit - by protecting our environment and saving money too.

"My constituency office in Perth is already part of the Refill scheme and I would encourage organisations and businesses across Scotland to sign up too.
From BBC news