Treat water, then retest. Lead is a metal found in natural deposits. It is sometimes used in household plumbing materials or in water service lines used to bring water from the main to the home. Lead may occur in drinking water either by contamination of the source water used by the water system, or by corrosion of lead plumbing or brass fixtures. Corrosion of plumbing is by far the greatest cause for concern.
All water is corrosive to metal plumbing materials to some degree.
Interference with red blood cell chemistry, delays in normal physical and mental development in babies and young children, slight deficits in the attention span, hearing, and learning abilities of children, and slight increases in the blood pressure of some adults. Often, first draw results are over the action level, and flushed results are below the action level. This is usually caused by corrosive water. Refrain from consuming water that has been in contact with your home's plumbing for more than six hours. Do not use water taken from the hot tap for cooking or drinking, and especially not for making baby formula .