Lead is a metal that occurs naturally in the environment. It is poisonous to humans and animals when consumed. Among other things, lead is commonly used in building construction, lead-acid batteries, bullets, weights and as a radiation shield. It also has been used in various components in household plumbing and well systems.
Download U.S. Geological Survey Report on lead in drinking water.
What are the health risks from lead?
According to the federal Agency for Toxic Substances and Disease Registry, the effects of lead are the same whether it enters the body through breathing or swallowing. Lead can affect almost every organ and system in your body.
How does lead get into drinking water?
The presence of lead in groundwater tends to be very small and almost undetectable.
A greater concern is the presence of lead in galvanized steel pipes, certain brass used in plumbing fixtures or well components, and certain solder used to connect pipes and joints. Although the lead content allowed in these plumbing and well components has been greatly reduced—most recently in 2014—it can still be a health risk for houses and/or well systems that pre-date federally mandated lead content reductions.
No amount of lead is safe, according to the National Institute of Health Sciences.
Two factors that can affect how much lead leaches into the water are:
- The length of time water is in contact with lead before being used
- The corrosiveness of the water due to either high pH or low pH.
How can I address unsafe levels of lead in my water?
First, try to determine the source of the lead in your water. If the groundwater coming into the well is not the problem, a water well system contractor can inspect your well system for any components that contain higher lead levels. A plumber may be able to help in identifying the sources of lead in the household plumbing.
If household plumbing or well system components are the source of unsafe levels of lead, the home owner has three basic options:
- Replace the problem components with new components that meet current federal requirements.
- Treat water that is being consumed with appropriate treatment technologies. The National Sanitation Foundation recommends the following:
“Potential treatment options for lead can include filters, reverse osmosis units, and distillers. Make sure the system is certified under NSF/ANSI standards for lead reduction, which means that the system has been independently verified to be able to reduce lead from 0.150 mg/L to 0.010 mg/L or less.
“If you have a private well and have high lead levels, the problem could be due to low pH. When pH levels drop below 7.0, water becomes acidic which can cause lead to leach from plumbing fixtures. Acid neutralizing systems are generally used to correct this situation. By adding a chemical like soda ash to the water to boost pH above 7.0, the system can help reduce both lead and copper leaching attributable to low pH.
“If you do choose to use a water treatment system, remember that most water treatment systems have replaceable components or require regular service, so be sure to follow the manufacturer’s maintenance instructions and replace filters at the recommended interval.”
- Flush water that has been sitting in your water system for a long time (such as overnight) to remove water into which lead has leached. You may need to take several water samples from different taps to determine how to effectively flush your system for the purpose of lead reduction in drinking water. Water that is being flushed can be used for purposes that do not involve ingestion.
The preceding options vary in cost and ease of implementation, so that what works best for one well owner may not have the same advantages for another.