All it takes for backflow conditions to occur is a drop in line pressure in the water main, which can happen due to use of hydrants for fire fighting, water main break, high usage or backpressure. In America, we all assume when we turn the tap on that we have safe drinking water. This is a luxury we enjoy, but not without very strong regulations and considerable expense. Our drinking water is among the safest in the world. Water protection and conservation requires the effort and cooperation of everyone.