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Orthophosphate added to drinking water to reduce lead levels

Starting Monday, August 23, 2004 the Washington Aqueduct will begin adding orthophosphate to the finished drinking water supply in an effort to reduce lead leaching from pipes into drinking water. The areas where orthophosphate is being added include the District of Columbia, Arlington, Falls Church, Vienna, and parts of northeastern Fairfax County serviced by Falls Church.

Orthophosphate is a commonly used corrosion inhibitor that forms a protective coating on the inside of service lines and household plumbing. It is a food grade chemical and is generally recognized as safe by the Food and Drug Administration and is certified for use by the National Sanitation Foundation. It is expected that reduced lead levels in water may be realized within one year.

To learn more about the orthophosphate treatment in the Washington Aqueduct System you may attend one of two community meetings to be held from 6:00 to 8:30 on Thursday August 19, 2004 at the Congress Heights United Methodist Church and on August 24, 2004 at the Martin Luther King Library. For more information on these community meetings or drinking water contact the DC Water and Sewer Authority at (202) 787-2732, US Army Corps of Engineers Washington Aqueduct at (202)764-2573 or the DC Department of Health at (202)671-0733.

For information about the use of Orthophosphate in other metropolitan area water utilities contact individual utilities.

1. What is orthophosphate and why is it being added to my drinking water?

Orthophosphate is a food-grade chemical and is generally recognized as safe by the Food and Drug Administration. It is certified for use in drinking water treatment by the National Sanitation Foundation, and is used widely as a food acidifier in soft drinks.

Orthophosphate, is a commonly used as a "corrosion inhibitor," which when added to finished drinking water will form a protective coating on the inside of service lines and household plumbing reducing lead leaching into drinking water. Starting August 23, 2004, it is being added to the drinking water supplies in DC, Arlington, Falls Church, Vienna, and in parts of northeast Fairfax County served by Falls Church.

2. How long will it take to see reduced lead levels once the orthophosphate has been added?

According to EPA, there should be noticeable results within a year in areas with lead drinking water problems, although it could take longer before lead levels below the federal safety action level are achieved.

3. The addition of orthophosphate may cause drinking water to temporarily turn reddish-orange (red water). What causes this color change and what should I do?

The addition of orthophosphate in drinking water may cause iron to dissolve from water pipes into the water. The color change is temporary and will normally go away by running your cold water until it is clear. Do not drink, cook, wash clothes or use hot water that is discolored. If after repeated flushing the problem persists, then contact your water utility.

4. Will the addition of orthophosphate impact sewage plants or pollute the Chesapeake Bay?

According to EPA no it will not.