English: A picture of a roll of Carlisle Co.-made EPDM-foil. This foil (used for waterproofing roofs) does not pollute any rainwater running off the foil (unlike other contemporary waterproof foils as bitumen). Having the runoff rainwater unpolluted allows the rainwater to be used by the house owners for their sanitary requirements (which is being done by the owners here). This is known as rainwater harvesting. Note the front and back, which are noticeably different, as well as the part of the foil which is sticky (to attach it unto the roof).