Frequently Asked Questions taken from: EPA General Information about Lead in Drinking Water

How does lead get into drinking water?
Lead can enter drinking water when plumbing materials that contain lead corrode, especially where the water has high acidity or low mineral content that corrodes pipes and fixtures.  Lead pipes, faucets, and fixtures are the most common sources of lead in drinking water.  Lead service lines, the lead pipes that connect the home to the water main, are typically the most significant source of lead in water.  Lead pipes are more likely to be found in older cities and homes built before 1986.  Brass or chrome-plated brass faucets and plumbing with lead solder are the most common problems in homes without lead service lines.

Is there a safe level of lead in drinking water?
The Safe Drinking Water Act (SDWA) requires the Environmental Protection Agency (EPA) to determine the level of contaminants in drinking water at which no adverse health effects are likely to occur with an adequate margin of safety.  For most contaminants, EPA sets an enforceable regulation called a maximum contaminant level (MCL) based on the maximum contaminant level goal.  The EPA has set the maximum contaminant level goal for lead in drinking water at zero because lead is a toxic metal that can be harmful to human health even at low exposure levels.  However, lead contamination of drinking water often results from corrosion of the plumbing materials belonging to water system customers.  Therefore, EPA established a treatment technique rather than an MCL for lead.  A treatment technique is an enforceable procedure or level of technological performance which water systems must follow to ensure control of a contaminant.  If more than 10 percent of tap water samples exceed the lead action level of 15 parts per billion, then water systems are required to take additional actions including:

  • Taking further steps optimize their corrosion control treatment (for water systems serving 50,000 people that have not fully optimized their corrosion control).
  • Educating the public about lead in drinking water and actions consumers can take to reduce their exposure to lead.
  • Replacing the portions of lead service lines (lines that connect distribution mains to customers) under the water system’s control.

What effect does lead have on children?
Young children, infants, and fetuses are particularly vulnerable to lead because the physical and behavioral effects of lead occur at lower exposure levels in children than in adults. A dose of lead that would have little effect on an adult can have a significant effect on a child. In children, low levels of exposure have been linked to damage to the central and peripheral nervous system, learning disabilities, shorter stature, impaired hearing, and impaired formation and function of blood cells.

Even low levels of lead in the blood of children can result in:

  • Behavior and learning problems
  • Lower IQ and hyperactivity
  • Slowed growth
  • Hearing problems
  • Anemia

In rare cases, ingestion of very high levels of lead can cause seizures, coma and even death.

What effect does lead have on pregnant women?
Lead can accumulate in our bodies over time, where it is stored in bones along with calcium.  During pregnancy, calcium is released from bones as maternal calcium and is used to help form the bones of the fetus.  Lead can be released during this process.  This is particularly true if a woman does not have enough dietary calcium.  Lead can also cross the placental barrier exposing the fetus to lead.  This can result in serious effects to the mother and her developing fetus, including:

  • Reduced growth of the fetus
  • Premature birth

Where can I go to have my home, including the water, tested for lead?
Homes connected to public water systems need to contact their public water system administrator for information about water testing.

The Department of Health and Senior Services recommends private drinking well water be tested at least once each year and anytime the well is serviced or the water changes in look, smell, or taste.  To receive a State Public Health Laboratory issued test request form, water sample collection kit, and sample collection instructions, contact your local public health agency.  Search the Directory of Local Public Health Agencies by city or county.  Or, you may contact the Bureau of Environmental Epidemiology at 573-751-6102, toll free 866-628-9891, or info@health.mo.gov.