Final TMDLs Approved by EPA: Upper North Branch Potomac River

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 (basin number 02141005) on the State’s 303(d) List submitted to the U.S. Environmental Protection Agency by MDE as impaired by nutrients (1996), sediments (1996), pH (1996), metals - unspecified (1996), methylmercury (2002), and portions of the basin for impacts to biological communities (2002 and 2004).  The designated use of the Upper North Branch Potomac River is Use I-P (Water Contact Recreation, Protection of Aquatic Life, and Public Water Supply).  The document available below establishes a TMDL for sediments in the Upper North Branch Potomac River Watershed to allow for the attainment of the above mentioned designated use.  The objective of the sediment TMDL established in this document is to ensure that there will be no sediment impacts affecting aquatic health, when aquatic health is evaluated based on Maryland’s biocriteria, thereby establishing a sediment load that supports the Use I-P designation for the Upper North Branch Potomac River Watershed.  The watershed sediment load includes the potential effects for water clarity and erosional and depositional impacts, thus accounting for all of the sediment impacts that indicate a sediment impairment per the Maryland 303(d) listing methodology.

A WQA of eutrophication for the nutrient listing has been submitted to the EPA (2006).  The listings for bacteria, low pH, metals, and impacts to biological communities will be addressed separately at a future date.

In conjunction with the renewal of the Backbone Mountain, LLC permit renewal (NPDES#MD0068811)(April 2014), updates are being made to the Total Maximum Daily Load (TMDL) of Sediment in the Upper North Branch Potomac River Watershed, Garrett County, Maryland. To allow for easier revisions to the TMDL in the future, if needed, Sections 2.2.2 and 4.6 have been updated to remove the total number of permits in the watershed.  Appendix B has been modified to incorporate corrected point source information in the Waste Load Allocation (WLA) calculations and to provide consistency with the approach applied for process water facilities within the Chesapeake Bay nutrient and sediment TMDLs.  In this modification, only the individual WLAs to the facilities included within the total WLA and the manner in which this information is presented has changed; the overall WLA remains the same.  The TMDL, Load Allocation (LA), and WLA remain the same.   

Total Maximum Daily Load of Sediment in the Upper North Branch Potomac River Watershed, Garrett County, Maryland

(Approved on May 15, 2007)

EPA's Decision Letter EPA's Decision Letter
Revised Final Main Report TMDL_UNBPotomac_sed_revised_final.pdf
(738 KB)
Main Report TMDL_UNBPotomac_sed.pdf (1035KB)

Comment Response Document

CRD_UNBPotomac_sed.pdf (5KB)

Contact Information

Please direct questions or comments concerning this project to Maryland's TMDL Program at (410) 537-3818.