Final TMDLs Approved by EPA: Back River

The Back River Watershed is located in the western shore region of Maryland, northeast of the Baltimore Harbor and it drains into the Chesapeake Bay. It is located on the western shore of the Upper Chesapeake Bay about 160 miles from the Virginia Capes at the entrance to the Bay. It is a relatively small estuary, with average depths of approximately 25 feet (near the mouth), nine feet (lower estuary), and five feet (upper estuary). The basin is part of the Patapsco/Back River Tributary Strategy Basin.

The tidal stream segment of the Back River (basin number 02130901) was first identified on the 1996 303(d) list submitted to EPA by the Maryland Department of the Environment (MDE) as being impaired by nutrients due to signs of eutrophication, expressed as high chlorophyll a levels. Eutrophication is the over-enrichment of aquatic systems by excessive inputs of nutrients (nitrogen and/or phosphorus). The nutrients act as a fertilizer leading to the excessive growth of aquatic plants. These plants eventually die and decompose, leading to bacterial consumption of dissolved oxygen (DO). For these reasons, the document available below establishes TMDLs for the nutrients nitrogen and phosphorus in the Back River. The Back River was also identified on the 303(d) list as being impaired by bacteria (fecal coliform), toxics (PCBs), metals (Zinc) and suspended sediments. The impairments due to these contaminants have been or will be addressed in separate analyses by MDE.

Total Maximum Daily Loads of Nitrogen and Phosphorus for the Back River, Baltimore City and Baltimore County, Maryland

Approved on June 29, 2005

EPA's Decision Letter EPA's Decision Letter
Main Report  backriver_tmdl_eutro_final.pdf (1522KB)
Appendix 1 Part A backriver_appendix1A_eutro_final.pdf (825KB)
Appendix 1 Part B backriver_appendix1B_eutro_final.pdf (1351KB)
Appendix 1 Part C backriver_appendix1C_eutro_final.pdf (796KB)
Appendix 1 Part D backriver_appendix1D_eutro_final.pdf (289KB)
Point Source Tech Memo backriver_pstechmemo_eutro_final.pdf (90KB)
Non-Point Source Tech Memo backriver_npstechmemo_eutro_final.pdf (90KB)
Comment Response Document backriver_CRD_eutro_final.pdf (83KB)

Contact Information

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