While the EPA has worked to remove lead from drinking water over the years, it can still exist in trace amounts in drinking water. Here are the most common sources of lead in drinking water.
If your home was built prior to the 1980s, it's likely to have lead solder connecting the copper water pipes. Lead found in tap water often comes from corrosion of plumbing fixtures or the solder connecting the pipes. Today's plumbing fixtures must pass rigorous tests and be certified to contain levels of lead that are below safety thresholds.
Some major U.S. utilities use lead pipes to supply water from to homes and businesses. Because the pipes have been in use for a long time, they have formed a natural oxidation barrier that prevents lead from leeching into the water. Utilities will often add lime or orthophosphates as an additional barrier to prevent lead from getting into drinking water.
If you're concerned about lead in your home's drinking water, regular testing can help ensure that levels are safe to drink. In addition, EPA has an online guide called “How to Identify Lead Free Certification Marks for Drinking Water System & Plumbing Products” that can help you choose the right plumbing fixtures for your home.