Water Quality Analysis of Zinc for the Back River, Baltimore County and Baltimore City, Maryland

Water Quality Analyses (WQA) with EPA Concurrence of MDE's Findings: Back River

The Back River watershed is located in the Patapsco/Back River region of the Chesapeake Bay watershed within Maryland

Back River (basin code 02130901), located in Baltimore County and Baltimore City, MD, was identified on the State’s list of water quality limited segments (WQLSs) as impaired by nutrients (1996 listing), suspended sediments (1996 listing), chlordane (1996 listing), polychlorinated biphenyls (PCBs) - sediments (1998 listing), zinc (Zn) (1998 listing), fecal coliform (2002 listing) and impacts to biological communities (2002 listing).  All impairments were listed for the tidal waters except for the impacts to biological communities, which are listed for the non-tidal region.  Code of Maryland Regulations (COMAR) defines the Back River as a fresh waterbody.   The report available below provides an analysis of recent monitoring data, including hardness data, which shows that the aquatic life criteria and designated uses associated with Zn are being met in the Back River.  The analyses support the conclusion that a TMDL for Zn is not necessary to achieve water quality standards in this case.  Barring the receipt of any contradictory data, this report will be used to support the removal of the Back River from Maryland’s list of WQLSs for Zn when the Maryland Department of the Environment (MDE) proposes the revision of Maryland’s 303(d) list for public review in the future.  The listings for nutrient, PCBs, suspended sediment, fecal coliform and impacts to biological communities will be addressed separately at a future date.  A TMDL for chlordane was completed in 1999.  A TMDL for nutrients was completed in 2004.

WQA of Zinc for the Back River,
Baltimore County and Baltimore City, MD

(Concurrence December 23, 2004)

EPA's Decision Letter

EPA's Decision Letter

Main Report 

WQA_backriver_zinc.pdf

Comment Response Document

CRD_backriver_zinc.pdf
 

Contact Information

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