I'll try to clear up the confusion, as I partly started it anyway.
Bleu Sud is THE main Bleu site, alonside the 'burnup road' as Fran succinctly puts it, where the toilet block is located.
The Bleu overflow field, sometime called Bleu Annexe, is a bit further down the back lane towards Arnage ( the lane between the camp site and the car park), and it is this overflow field that does not have standpipes. However, as Barry states, there is usually someone with a looooooooong length of hose that will bring water into the field.
Hope this clears it up.
Del