Utility Department

Lead FAQs

How does lead get into my water?
How much lead is harmful?
What can I do to avoid drinking lead?
Does my house's age make a difference?
When were houses constructed with 100%-lead-free pipes?
How does time affect lead levels?

How does lead get into my water?
Lead is a toxic metal that has been used in the construction of most household plumbing systems in Wisconsin. Water within the plumbing system will continuously dissolve the lead it contacts. The rate can vary greatly with variations in natural water quality and the age of the plumbing system. Most water in Wisconsin is corrosive enough to dissolve some amount of lead. When the water stands motionless for extended periods of time, such as overnight, lead concentrations in the water can sometimes increase greatly.
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How much lead is harmful?
There is growing evidence that even moderate levels of lead can be harmful to human health, and particularly to the health of small children and developing fetuses.
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What can I do to avoid drinking lead?
For this reason, Wisconsin residents are advised to: 1. Run your water in the morning for two or three minutes, or until it gets as cold as it will get, before you drink it; or 2. Find out how much lead your water is dissolving from your plumbing system.
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Does my house's age make a difference?
The age of a house relates to the type of plumbing system that can be expected. Through the early 1900s, lead pipes were commonly used for interior plumbing in some areas. Until the 1940s, lead piping was often used for the service lines that join buildings to street water mains. Lead piping can be recognized as a dull-grey metal which is soft enough to be easily scratched with a house key or screwdriver. Scratched lead will be shiny underneath.

Studies indicate that the levels of dissolved metals in drinking water will decrease as a building ages. This is because, as time passes, a mineral or oxidation coating forms on the inside of the pipes (if the water is not too corrosive). This coating can partially insulate the water from the lead materials, significantly reducing levels of dissolved lead.
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When were houses constructed with 100%-lead-free pipes?
In the 1930s, copper pipes or galvanized steel pipes replaced lead pipes in most residential plumbing. However, the use of 50/50 tin/lead solder and lead-containing fluxes to join copper piping continued in Wisconsin until a ban on the use of lead solder and fluxes became effective on September 26, 1984. Homes constructed after that date should have "lead-free" water supply plumbing systems. Also, any repairs of existing plumbing systems must be made with "lead-free" materials, such as tin/antimony (95/5) solder.
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How does time affect lead levels?
The longer water stands in a pipe the more lead can be dissolved. Because lead will continuously dissolve into the water, the resulting lead concentrations will increase directly with time. This is why water which is drawn first thing in the morning, or after any extended period of non-use, will contain the highest levels of lead.
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For additional information regarding lead and copper, see the Wisconsin Department of Natural Resources Web Site at http://www.dnr.state.wi.us/org/water/dwg/.