1 Water Quality in the Anacostia River Tony Smith December 1, 2005

2 Introduction  Purpose: identify sources of contaminant  Data NHD (USGS) NED (USGS) Land cover (USGS) USGS bioavailability studies (Phelps 2002, 2003, 2004)  Conclusion

3 PAHs  Polycyclic aromatic hydrocarbons occur naturally produced in combustion reactions  Known or suspected carcinogens and mutagens  Integrated Risk Information System RfD (naphthalene): 20 μg / kg day (estimate of daily exposure to population without appreciable deleterious effect)

4 The Anacostia River  Watershed covers 176 square miles home to 800,000  Three main drainage areas northwest (32%) northeast (45%) Tidal (23%)  : spills totaling 60,000 gallons  “One of America’s 10 worst rivers”

5 HUC Middle Potomac-Anacostia-Occoquan

6 Land Cover

7 Catchments and Industry

8 Predictions based on land cover  High concentrations in tidal drainage streams  Little contaminant contribution from NW and NE branches

9 PAH concentrations, 2001

10 PAH Concentrations, 2002

11 PAH Concentrations, 2003

12 Summary of Data and Conclusion  20 of 23 higher than reference (p<0.05)  Clam survival 6 – 98%  NE and Tidal Branches are primary contributors Beltsville Agricultural Research Center is US EPA National Priority Site US Navy Yard, Washington Gas Light Facility

13 PAH Concentrations, 2002

14 Additional Factors  Sediment Stream gage Suspended sediment Precipitation  Frequency of water quality monitoring  Scope of land cover classification  EPA Priority Sites

15 Thanks