Portable loos may be up there on the worst things about festivals, but failing to use one at Glastonbury this weekend could lead to the whole shebang being shut down.

This might sound a tad extreme, but if too many people start weeing all over Worthy Farm, the Environment Agency has the power to say enough is enough and close the site.

Glastonbury organisers posted a message on the event's official website titled 'Please don't pee on the land' in a bid to encourage ticket-holders to consider the environment.

Basically what happens is that weeing on the ground causes "toxic pollution of the water table" as urine runs into the Whitelake River and depletes it of oxygen, while also flowing down into the valley, polluting miles of countryside.

The statement explains that if 135,000 revellers start peeing everywhere, wildlife and fish will not be at all happy, so the Environment Agency will be testing the water regularly during the festival.

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Thousands of loos have been installed across the huge Glastonbury site, with environmental health students on hand to check and clean them twice a day. Rumour has it there will be plenty of free loo paper up for grabs too.

You can see where the loos will be located on the map below:

(Pic: Glastonbury Festival)