Water Quality Analyses (WQA) with EPA Concurrence of MDE's Findings: Liberty Reservoir

The Liberty Reservoir watershed is located in the Patapsco region of the Chesapeake Bay watershed within Maryland.  The watershed covers portions of Baltimore and Carroll County.   The Reservoir is owned by the Baltimore City Department of Public Works and is situated in the Patapsco River watershed. 

Inflow to Liberty Reservoir is primarily via the northern branch of the Patapsco River with additional inflow from Morgan Run and several small tributaries.  Discharge from the reservoir is into the Lower North Branch of the Patapsco River.  The reservoir is currently used for recreational activities (swimming, fishing and boating) and as a major water supply for the City of Baltimore.  Upstream watershed usage includes a water supply for the Carroll County Department of Public Works, an unnamed park surrounding the reservoir and Soldiers Delight Natural Environmental area.  Downstream usage includes Patapsco Valley State Park. 

The Liberty Reservoir (basin code 02130907), located in Baltimore and Carroll Counties, MD, was identified on the State’s list of water quality limited segments (WQLSs) as impaired by chromium (Cr) (1996 listing), lead (Pb) (1996 listing), nutrients (1996 listing), suspended sediments (1996 listing), fecal coliform (2002 listing), methylmercury (2002 listing) and evidence of biological impacts (2002 listing).  The Cr, Pb, nutrients, suspended sediment and methylmercury impairments were listed for the impoundment, and the fecal coliform and biological impairments were listed for the non-tidal streams.  The report available below provides an analysis of recent monitoring data, including hardness data, which shows that the aquatic life criteria for Cr and Pb and the designated uses supported by those criteria are being met in the Liberty Reservoir.  The non-tidal streams are not listed for Cr or Pb, therefore they are not addressed in the water quality analysis (WQA).  The analysis supports the conclusion that TMDLs for Cr and Pb are not necessary to achieve water quality standards in this case because the standards are already being met.  Barring the receipt of any contradictory data, this report will be used to support the removal of the Liberty Reservoir impoundment from Maryland’s list of WQLSs for Cr and Pb when the Maryland Department of the Environment (MDE) proposes the revision of Maryland’s 303(d) list for public review in the future.  A TMDL for methyl mercury in fish tissue was completed in 2002.  The nutrient, suspended sediments, fecal coliform and biological impairments will be addressed separately at a future date. 

WQA of Chromium and Lead for Liberty Reservoir Impoundment, Baltimore and Carroll Counties, MD

(Concurrence November 10, 2003)

EPA's Decision Letter

EPA's Decision Letter

Main Report 


Comment Response Document



Contact Information

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