In 1991, the U.S. Environmental Protection Agency established guidelines for controlling lead and copper levels in public water supplies. The information contained in this presentation will discuss the health effects of copper and ways to reduce exposure to copper in drinking water.
For a free brochure containing the information on this page, contact the nearest DNR office and request publication number WS-027.
Copper is a reddish metal that occurs naturally in rock, soil, water, sediment, and air. Its unique chemical and physical properties have made it one of the most commercially important metals. Since copper is easily shaped or molded, it is commonly used to make pennies, electrical wiring, and water pipes. Copper compounds are also used as an agricultural pesticide, and to control algae in lakes and reservoirs.
Copper also occurs naturally in plants and animals. It is an essential element for all known living organisms, including humans. However, very large single or long-term intakes of copper may harm your health.
Copper and its compounds are common in the environment. You may be exposed to copper by breathing air, eating food, or drinking water containing copper. You may also be exposed by skin contact with soil, water, or other copper-containing substances.
Copper forms different compounds when it joins with one or more other chemicals. These may be naturally-occurring or man-made. Most copper compounds found in air, soil, and water are strongly attached to dust or embedded in minerals, and cannot easily enter the body. These forms are not likely to affect your health. Other forms become dissolved in water and are not attached to other particles. In this form, copper is more likely to affect your health.
Levels of copper found naturally in ground water and surface water are generally very low; about 4 micrograms of copper in one liter of water (4 ug/1) or less. However, drinking water may contain higher levels of a dissolved form of copper.
High levels of copper occur if corrosive water comes in contact with copper plumbing and copper-containing fixtures in the water distribution system. If corrosive water remains motionless in the plumbing system for six hours or more, copper levels may exceed 1,000 ug/l. The level of copper in drinking water increases with the corrosivity of the water and the length of time it remains in contact with the plumbing.
Copper in our diet is necessary for good health. You eat and drink about 1,000 micrograms (1,000 ug) of copper per day. Drinking water normally contributes approximately 150 ug/day. Immediate effects from drinking water which contains elevated levels of copper include
The seriousness of these effects can be expected to increase with increased copper levels or length of exposure.
Children under one year of age are more sensitive to copper than adults. Long-term exposure (more than 14 days) to copper in drinking water which is much higher than 1,000 ug/I has been found to cause kidney and liver damage in infants. Other persons who are highly susceptible to copper toxicity include people with liver damage or Wilson's disease.
On the average, drinking water accounts for less than 5% of our daily copper intake. The U.S. Environmental Protection Agency (U.S. EPA) has determined that copper levels in drinking water should not exceed 1300 ug/l. No adverse health effects would be expected if this level is not exceeded. Measures should be taken to reduce exposure to copper if this level is exceeded.
Because copper exhibits these harmful health effects, and because drinking water may be a significant route of exposure to copper, it is important to know how much copper is in your drinking water. You may find that there is a metallic taste in your drinking water before copper levels are high enough to cause adverse health effects. You may also notice blue or bluegreen stains around sinks and plumbing fixtures. The only way to be certain of the copper level in your drinking water supply is to have the water tested. It is recommended that you use a laboratory that is state certified to analyze copper levels in drinking water.
If you are being served by a public water system, the owner of the utility will have results of copper sampling which has been done in parts of the distribution system. You may wish to consult the utility owner before testing your drinking water for copper.
The easiest and most effective method for reducing exposure to copper is to avoid drinking or cooking with water that has been in contact with your house plumbing for more than six hours. When first drawing water in the morning or after a work day, flush the system by running the cold water faucet for 2-3 minutes, or until the water gets as cold as possible. (If you live in an apartment complex, flushing the system may take longer). Water used for showering or washing also helps flush the system, but each faucet where water is drawn for drinking or cooking purposes should be flushed separately.
Another option for reducing your exposure to copper is to purchase bottled water. This may be a useful option, particularly if it will be used by young children as drinking water, or for making infant formula. However, you should exercise care to obtain bottled water which meets all drinking water standards.
If you are experiencing elevated copper levels in drinking water, it may be likely that lead levels are also elevated. This is especially true if the plumbing system in your home or apartment contains lead solder joints, lead service lines, or brass fixtures. Since lead and copper enter drinking water under similar conditions, it is advisable to test for lead when testing for copper.
The U.S. EPA promulgated National Primary Drinking Water Standards for lead and copper on June 7, 1991. These standards are applicable to all public water systems, and require them to begin monitoring for lead and copper at consumer taps no later than July, 1993. If the EPA action level of 1,300 ug/l for copper is exceeded, the utility must conduct further testing to determine if the corrosivity of the water is contributing to an increase in the copper levels. They are also required to implement optimum corrosion control measures to reduce the corrosivity of the water to acceptable levels. If you have questions regarding copper monitoring, contact your water utility.
If you need additional information regarding copper in drinking water contact the DNR statewide office in your area. Also, the Division of Health can provide additional information on the health effects of copper.
For more information, contact: Margie Damgaard, IS Professional, Public Water Section
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