Final TMDLs Approved by EPA:  Upper North Branch of the Potomac River Watershed

The North Branch of the Potomac River forms the border between Maryland and West Virginia from its origin at the Fairfax Stone downstream to its confluence with the South Branch of the Potomac.  The Upper North Branch of the Potomac River is defined as the reach between its headwaters in West Virginia and its confluence with the Savage River.  The drainage area of the Upper North Branch Potomac River Watershed is 182,200 acres.  This consists of approximately 67,700 acres in Maryland and 119,500 acres in West Virginia.

The Maryland Department of the Environment (MDE) has identified the waters of the Upper North Branch Potomac River, located in Garrett County, as impaired by metals (1996 listing); metals – aluminum, iron, manganese (2008 listings); sediments (1996 listing); nutrients (1996 listing); low pH (1996 listing); and impacts to biological communities (2002/2004 listing). A water quality analysis (WQA) to address the 1996 metals listing was developed by MDE and approved by EPA in 2006. The WQA determined that a TMDL for metals in the entire Upper North Branch Potomac River 8-digit watershed was not necessary to achieve water quality standards, but, as explained below, impairments were identified in certain tributaries and a portion of the river’s mainstem. This TMDL document addresses the listings for aluminum and iron in the specified areas of the watershed. A TMDL for sediment was approved by EPA in 2007. A TMDL to address the listing for low pH was approved by EPA in 2008. The listings for manganese and impacts to biological communities will be addressed separately at a future date.

The document, available below, establishes Total Maximum Daily Loads (TMDLs) for iron and aluminum in the Upper North Branch Potomac River watershed (8-digit assessment unit MD-02141005).


Total Maximum Daily Loads TMDLs of Iron and Aluminum for the Upper North Branch Potomac River Watershed, Garrett County, MD

Approved on February 15, 2011

EPA's Decision Letter

EPA's Decision Letter (763KB)

Main Report  UNB_Potomac_Al_Fe_final.pdf (5655KB)
Appendix A UNB_Potomac_Al_Fe_AppnA_final.pdf (106KB)
Appendix B UNB_Potomac_Al_Fe_AppnB_final.pdf (235KB)
Appendix C UNB_Potomac_Al_Fe_AppnC_final.pdf (642KB)
Appendix D UNB_Potomac_Al_Fe_AppnD_final.pdf (302KB)
Appendix E UNB_Potomac_Al_Fe_AppnE_final.pdf (172KB)
Appendix F UNB_Potomac_Al_Fe_AppnF_final.pdf (175KB)
Comment Response Document UNB_Potomac_CRD_Al_Fe_final.pdf (12KB)


Contact Information

Please direct questions or comments concerning this project to Maryland's TMDL Program at (410) 537-3572.


Acrobat® Reader is required to view and print the PDF files. If you do not have it click on the icon to the right. Get Acrobat Reader (its Free!)