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Trace Compounds Research

Overview

Fairfax Water, the Washington Aqueduct, and the Washington Suburban Sanitary Commission, suppliers of over 90 percent of the COG region’s drinking water, have taken regional efforts to monitor for the presence of trace compounds (often referred to as emerging contaminants) in source water (stream water collected at a surface- water intake) and finished water (water that has gone through the treatment process, but has not been distributed). Working with national partners, these three major drinking water suppliers tested the Potomac, Patuxent, and Occoquan source waters for emerging contaminants.  Emerging contaminants, such as endocrine disrupting compounds (EDCs), pharmaceuticals, and personal care products (PPCPs), are commonly described as chemicals or materials that have a real or perceived threat to human health or the environment. 

The utilities tested for nineteen (19) compounds in the source and treated waters. Water samples were sent to a laboratory certified for this type of analysis. 

Out of nineteen compounds tested for, the results showed the presence of very, very small amounts of a total of four compounds—Atrazine, Carbamazepine, estrone and Sulfamethoxazole—in the three rivers and in some of the treated drinking water, confirming the results of earlier monitoring studies. The compounds detected were found at the part per billion and part per trillion levels. A part per billion is equal to one gallon of water in 1,514 Olympic-size swimming pools.  A part per trillion is equal to one gallon of water in 1,514,570 Olympic-size swimming pools. Research to date shows that there is no indication of human health concern at these levels.

The regional drinking water utilities, along with other water utilities nationally, are working to advance the science in the area of understanding and treating these emerging contaminants in water.  The Potomac Drinking Water Source Partnership, founded by Fairfax Water, the Washington Suburban Sanitary Commission and the Washington Aqueduct, will continue to study water quality issues in the Potomac watershed. Monitoring among the regional water utilities will be ongoing.

Links

For more information about the testing and results of the source and finished water study conducted in the COG region, see the following documents:

Frequently Asked Questions (PDF)

Table Description of 19 Compounds Tested (PDF)

Testing Results (PDF)

Potomac Drinking Water Source Partnership's Overview of Emerging Contaminants (HTML)

Abstract of American Water Works Association Research Foundation (AwwaRF) Study of EDCs and Pharmaceuticals in Drinking Water (PDF)

Water Utility web sites:

Fairfax Water

• Special Statement on Trace Compounds by Fairfax Water

Washington Aqueduct

Washington Suburban Sanitary Commission

• Pharmaceuticals in Drinking Water-WSSC
  

USGS and Washington Aqueduct Public Briefing

In addition to the regional study described above, the Washington Aqueduct was also part of a larger study of trace compounds in 9 watersheds across the nation, including the Potomac, completed by the U.S. Geological Survey (USGS).

The National Water-Quality Assessment (NAWQA0 program of the USGS tested source and finished water for approximately 280 anthropogenic compounds, which are primarily unregulated under EPA Federal Drinking-water Standards. Samples were taken by USGS monthly during 2003-05.

The Washington Aqueduct and USGS held a public briefing about their studies on December 5, 2008 at the Cannon House Office Building. The briefing was entitled Low Level Organic Chemicals in Surface-Water Sources of Drinking Water.

Briefing materials may be accessed on the USGS web site:
http://water.usgs.gov/nawqa/swqa/