Backflow is the reversal of the flow of water or mixtures of water and other unwanted substances from any source (such as used water, industrial fluids, gasses, etc.) into the distribution water mains or pipes of the water system.
Water distribution systems are designed to flow in one direction from the main to the customer. When the direction of flow is reversed due to pressure differences, (such as fire fighting efforts, a water main break, or consumer high side pressure (pumped)) , backflow can allow contaminants to enter the potable drinking water system through cross-connections. When this happens, any substance that may be in contact with the water supply main or line could be siphoned into the public water system.
A single backflow incident can potentially affect hundreds or even thousands of people. Preventing the backflow of contaminants and pollutants in the water system is absolutely essential if health and property are to be protected.
