Introduction to Lead and

​Lead Service Line Replacement

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Why is lead a problem? 

Lead exposure can harm children’s brain development, contributing to lower IQs as well as learning and behavioral problems. Young children, infants, and fetuses are particularly vulnerable to lead because the harm appears to be greater at lower exposures in children than in adults.

How does lead get into drinking water?

Lead can enter drinking water when pipes and plumbing fixtures that contain lead corrode, especially where the water has high acidity or low mineral content. There are three main sources of lead:
  • Lead pipes - Lead service lines, the pipe that connects the water main under the street to a building’s plumbing. Lead pipes were also used in inside plumbing but it is unusual. Congress banned use of lead pipes in 1986. 
  • Leaded solder – Solder is used to connect copper pipe and fittings.  Congress banned the use of leaded solder in 1986.​
  • Leaded alloys – Brass is frequently used in faucets and other plumbing components.  In 1986 Congress limited the amount of lead in brass to 8% (close to the level of lead typical of products at the time) and later in 2014 reduced the limit to a much lower level (0.25%).​
Collaborative fact sheet on lead:Resources on the risks of lead:
​While leaded solder and brass can be important sources of lead in drinking water, the Collaborative is focused solely on LSLs. ​

What is a service line?

The following figure is a simplified illustration of the components of a service line installation.  
Each service line or connection consists of multiple components. Common terms for these components are listed below. The name of the valves and the locations of the valves and meter may vary, so alternate terms also are listed in the definitions. The following are commonly used terms starting at the water main:​
​
  • Corporation stop - A valve, which provides a reliable point of connection to the water main.​ This may also be known as a ferrule, corp stop, or corporation stopcock. This valve is often made of brass, and is not readily accessible without excavation.​
  • Service line – The pipe connecting the water main to the interior plumbing in a building. Portions of this pipe are sometimes given specific names. The length of pipe between the main and curbstop (or outside meter pit) may be referred to as the “communication” pipe. The pipe from the curbstop (or outside meter pit) to the building is frequently called a “supply” pipe. A short piece of flexible piping from the corporation stop on the main to the pipe that extends to the curbstop is called a gooseneck. Lead was used for goosenecks because it was durable and easily bent.  In modern installations flexible piping materials (e.g., copper, plastic) are used for the service, and separate goosenecks are not necessary. Another name for the gooseneck is a pigtail. ​​
  • Curbstop - An exterior valve used to turn on and off water service to the building. When located at or near the property line, this valve is called a curb stop. It usually is placed in a small vault-like box called a curb box or valve box. The curb box has a lid that allows the buried value to be accessible to utility workers in the event a repair is needed. Some utilities may include this valve in an outside meter pit rather than in a separate curb box. Some utilities do not use this valve.
  • Shutoff-valve - The valve located where the service line enters the home and connects to the interior home plumbing that allows the customer to turn off water to the building in order to make repairs.​
Lead gooseneck
  • Water meter - The device to measure the amount of water used by the building occupants. That volume generally is used to calculate the customer’s water bill.  Meters may be located inside or outside the home. Meters are often located inside the home in communities that experience long periods of cold weather.​​
Learn about the role of public health professionals in LSL replacement.

What is full LSL replacement?

Full LSL replacement involves elimination of lead pipe from a water main up to the interior plumbing of the home. Older brass components would also typically be replaced, though some brass components might remain after replacement in some instances. An example would be a brass valve functioning as a corporation stop where replacement would require shutting off water to multiple homes or increase the risk of a leak or break in the water main.

Why is full LSL replacement important?

​Even if your community has a water system with effective corrosion control and low drinking water lead levels, LSLs can contribute unpredictable and variable sources of exposure. For homes with LSLs, the service line typically contributes the greatest percentage of lead to the tap. Lead particulates from an LSL may enter directly into the water people drink or become trapped in the faucet aerator and release lead over time. With the reduction of lead in new plumbing material, the next large opportunity for reducing the risk of exposure to lead in drinking water is the removal of LSLs.
Research into partial LSL replacement demonstrates increased release of lead particulate into drinking water due to disturbance of lead service lines. These particulates may enter directly into the water people drink or become trapped in the faucet aerator and release lead over time. The Collaborative encourages full LSL replacement.

Controlling corrosion

Corrosion is a dissolving or wearing away of metal caused by a chemical reaction between water and your plumbing.  A number of factors are involved in the extent to which lead enters the water, including:
  • the chemistry of the water (acidity and alkalinity) and the types and amounts of minerals in the water,
  • the amount of lead it comes into contact with,
  • the temperature of the water,
  • the amount of wear in the pipes,
  • how long the water stays in pipes, and
  • the presence of protective scales or coatings inside the plumbing materials.
 
Understanding the corrosion control strategy used by a community’s water utility and the effectiveness of that strategy is important to planning for LSL replacement. Source water characteristics determine corrosion control practice. So, having an appreciation of both the current water supply and future changes in source water informs a community’s analysis of lead release in their system.  When corrosion control is not effectively reducing release of lead, the LSL replacement should take the increased risk of lead release into account.

Controlling corrosion is a priority for utilities. But it cannot completely eliminate leaching of lead. Any home, including those with lead-free brass fixtures and solder may observe lead in their drinking water, but the following types of homes are more likely to have higher levels.
  • Older homes are more likely to have lead service lines and interior plumbing containing lead.
  • Homes with soft water, which has fewer dissolved minerals, and water that is more acidic and higher in dissolved oxygen can be more corrosive. 

Check with your local water utility to find out more about whether your water is corrosive and what can be done. Signs of corrosive water include frequent leaks, discolored water and stained dishes or clothes. You cannot see or taste lead in water; lead release can occur when other signs of corrosion are not present. All community water systems prepare a Consumer Confidence Report (CCR) for their customers each year. Contact your water utility if you'd like to receive a copy of their latest report.

If your water comes from a household well or other private water supply, check with your health department, or with any nearby water utilities about how to test your water.