Sources of Contamination

How Lead Gets in Your Water

Corrosion of household plumbing systems; erosion of natural deposits.

While water doesn’t contain lead when it’s released by the treatment plant, it could contain dangerous levels by the time it reaches your sink.

Where the Lead Comes From

Certain additives dissolve metals and other minerals from pipes; chemicals, such as chloramines used to disinfect water, change water’s chemistry, making it more corrosive.

Water Main

Carries water from the treatment plant. It is rare for the water main to leach lead into the water.

Service Line

Connects each building to the water supply. Until a few decades ago, the lines commonly were made of lead. Even those installed since then might have some lead content.

Water Meter

Measures water use. Older meters could have high lead content. Even today's "lead-free" meters legally can contain as much as 8%.


Used to join pipes. After copper pipes replaced lead pipes, solder became a major contributor of lead contamination. Today's "lead-free" solder can contain no more than 0.2%.

Household Plumbing

Carries water through a home. Older homes may have lead pipes. Newer plumbing also may have substantial lead content, including "lead-free" pipes, which can contain as much as 8%.


Brass fixtures (which include many chromed fixtures) are most likely to contain lead. Like other water pipes and fixtures, "lead-free" faucets can contain as much as 8%