It is a familiar sight at the end of music festivals: masses of apparently abandoned tents. This photograph was taken at Electric Picnic at 2pm on Monday, when most of the 51,000 fans who attended the weekend festival had left the site, in Stradbally, Co Laois.

It is a problem that the event’s organiser, Festival Republic, will have to tackle next year, according Dr Cara Augustenborg of Friends of the Earth, who said that festivalgoers who abandoned their tents were being disrespectful. “It’s a sad way to end a great weekend.”

Everybody who brings a tent should have to pay a deposit, she said; it would be refunded only if they could show they were taking theirs home after the festival.

Although many people left their tents behind in the belief that they would be used by charities, many festival tents are unsuitable for any other use. Dr Augustenborg said that the 100 or so volunteers trying to salvage reusable equipment for eight charitable organisations find very little worth collecting, “so most waste is likely to be incinerated or end up in a landfill”.

One group, Jacket Off Your Back, appealed last year for Electric Picnic campers to donate their tents and sleeping bags; it found that many were too soiled to reuse.

An Electric Picnic spokeswoman said the photograph may be a misrepresentation, as at least 10,000 people were still on site when it was taken.