Hello everyone from today we are going to start play list about environmental videos.The first topic we will be discussing is water.Before knowing the standards lets knowing the words and its meaning we will be using through out the the videos of water.So lets startAir Break: A physical separation, which may be a low inlet into the indirect waste receptor from the fixtures, appliances or devices indirectly connected. Air Gap: (1) In a water supply system, it is the unobstructed vertical distance through the atmosphere between the lowest opening from any pipe or faucet supplying water to a tank, plumbing fixture or other device in the flood-level rim of the receptacle. (2) The unobstructed vertical distance between the inlet from the potable water system and the flood level rim of the non-potable water system, for a safe air gap, must be equal to at least twice the inside diameter of the inlet pipe. Backflow: The flow of water or other liquids, mixtures or substances, under positive or reduced pressure in the distribution pipes of a potable water supply from any source other than its intended source. Backflow Prevention Assembly: A device or means designed to prevent backflow or backsiphonage. Most commonly categorized as air gap, reduced pressure principle device, double check valve assembly, pressure vacuum breaker, atmospheric vacuum breaker, hose bibb vacuum breaker, residential dual check, double check with intermediate atmospheric vent, and barometric loop. Bottled Drinking Water: All water, which is sealed in bottles, packages or other containers and offered for sale for human consumption. Chemically Treated: Any water that has been chemically treated. The treatment may range from simple addition of chlorine to kill bacteria to multiple chemical applications to render it non-corrosive and/or non-scaling or to remove certain physical or chemical pollutants Coliform Group Bacteria: (1) A group of bacteria predominantly inhabiting the intestines of man or animal, but also occasionally found elsewhere. It includes all aerobic and facultative anaerobic, Gram negative, non-spore forming bacilli that ferment lactose with production of gas.