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

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

3. 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. 4 The Anacostia River  Watershed covers 176 square miles home to 800,000  Three main drainage areas northwest (32%) northeast (45%) Tidal (23%)  1988 - 1995: spills totaling 60,000 gallons  “One of America’s 10 worst rivers”

5. 5 HUC 02070010 Middle Potomac-Anacostia-Occoquan

6. 6 Land Cover

7. 7 Catchments and Industry

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

9. 9 PAH concentrations, 2001

10. 10 PAH Concentrations, 2002

11. 11 PAH Concentrations, 2003

12. 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. 13 PAH Concentrations, 2002

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

15. 15 Thanks