Lead in Drinking Water
Barbara Liukkonen, WRC Education Coordinator, author and contact
Marla Reicks, Extension Specialist, Food and Nutrition
Lead is a toxic heavy metal that serves no known useful functions in the body. Accumulation of lead in the body can cause damage to the nervous or gastrointestinal system, kidneys, or red blood cells. In extreme cases, it may lead to blindness, mental retardation, or death. Even moderate levels of lead may cause learning difficulties and stunted growth, or may endanger fetal development. Children, infants, and fetuses are the most sensitive populations.
Lead can enter the body through inhalation (breathing) or ingestion (eating or drinking). Airborne lead particles from industrial emissions or automotive exhaust may be inhaled; however, ingestion is the more common pathway for exposure. Lead can be contained in food or substances contaminated with lead (e.g. chips of lead-based paint, soil from near roads, and some home remedies).
Lead may also enter the body through contaminated drinking water. Lead rarely occurs naturally in drinking water, but it may be released from lead-based plumbing or solder by the corrosive action of water, particularly soft water.
Water for municipal supplies must meet the U.S. Environmental Protection Agency (USEPA) primary drinking water standards for contaminants when it is distributed. However, as water stands in the service pipelines and household plumbing, it may accumulate dissolved lead.
Throughout the early 1900s it was common to use lead piping for residential plumbing and for service connections to public water supplies. Since the 1930s, copper pipe has replaced lead pipe for almost all residential uses. However, lead-based solder was used to join copper piping until it was banned in 1986. Thus, older homes are more likely to have indoor lead plumbing or lead-based solder. In some neighborhoods, lead service lines connecting homes to water mains in the street are still common.
In 1991, the USEPA changed the primary drinking water standard for lead to reflect concern about lead accumulating as water stands in pipes or plumbing. The previous standard of 50 parts per billion (ppb) applied to water as it was distributed from municipal water systems. The new standard for lead is different from other drinking water standards and requires monitoring of lead concentration at high risk locations throughout the distribution system. The new rule requires that in at least 90% of the monitored households, lead levels at the tap must not exceed 15 ppb. The Minnesota Department of Health has established a Recommended Allowable Limit (RAL) of 20 ppb for private water supplies.
You may not be able to remove lead completely from your drinking water supply, but you can easily reduce your risk of exposure. You should run your cold water for 2 to 3 minutes before using the water for drinking or cooking, particularly first thing in the morning. This will flush out lead that has accumulated in the pipes overnight. Using the shower or doing laundry will help flush out the system, but you should still run the cold water for 15 to 30 seconds before drinking it.
Another method of reducing exposure is to avoid using water from the hot water tap for cooking, baking, or preparing baby formula. Hot water dissolves lead more readily than cold water. If you want hot water, use cold water and heat it on the top of the range or in the microwave.
Replacing the old plumbing and/or lead solder in your home will help reduce the levels of lead in your drinking water, but may not eliminate it completely if, there are lead service pipes. Replacing plumbing may also be very expensive.
Point-of-use water treatment may be effective in reducing high concentrations of lead in drinking water. Two recommended treatment methods are reverse osmosis and distillation systems.
If you live in an older home or are concerned that your family might be exposed to lead in drinking water, there are steps you can take to assess the presence of lead in your water. You can have your plumbing checked after considering whether your home is likely to have lead piping or lead-based solder. Check with your municipal water department to determine whether your household service line connection with the water main is lead.
Tests measuring lead levels in blood are available and may be appropriate for children and pregnant women. Check with your physician or community health professional.
The concentration of lead in your drinking water can be determined through a simple test, but there are specific procedures you must follow to ensure that the test is accurate. For information about lead in your drinking water supply or water testing services, contact your community health service or your Minnesota Extension Service county office.
For additional information about lead in drinking water, contact:
Barbara Liukkonen
Water Resources Education Coordinator
Water Resources Center
173 McNeal Hall
1985 Buford Ave.
Saint Paul, MN 55108
Phone: (612) 625-9256
Marla Reicks
Food Science and Nutrition
162 Food Science and Nutrition
University of Minnesota
1334 Eckles Avenue
St. Paul, MN 55108
(612) 624-4735
Minnesota Department of Health
Building:
Well Management Section
Environmental Health Division
Minnesota Department of Health
625 North Robert Street
St. Paul, MN 55155-2538
Mailing:
Well Management Section
Environmental Health Division
Minnesota Department of Health
P.O. Box 64975
St. Paul, MN 55164-0975
Phone: (651) 201-4600
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