Lead rarely occurs naturally in water. Lead may not be in your drinking water, but if it is, it typically enters your water after it leaves your local treatment plant or well. Lead is dissolved in water by corrosion of lead pipe or lead soldered pipe joints commonly found in the water distribution system.
Even if your home contains lead or lead soldered plumbing, you are not necessarily at risk. Over time, mineral deposits may form a coating on the inside of pipes which can prevent water from contacting lead plumbing materials. This coating usually takes years to form, and may not form at all. Lead plumbing materials have been identified as the primary source of lead contamination in drinking water today.