The Inner Harbor/Northwest Branch and the Bear Creek watersheds are located in the Patapsco/Back River region of the Chesapeake Bay watershed within Maryland. The Inner Harbor/Northwest Branch watershed is within Baltimore City; the Bear Creek watershed is within Baltimore County. The Northwest Branch watershed (embayment plus drainage area) covers 43,046 acres and includes the Jones Falls watershed, which flows into the Northwest Embayment. The Bear Creek watershed (embayment plus drainage area) covers 7,460 acres.
The Maryland water quality regulations state that all surface waters of Maryland shall be protected for water contact recreation, fishing, and protection of aquatic life and wildlife. Additionally, the specific designated use of the Baltimore Harbor, Northwest Branch, and Bear Creek portions of the Patapsco River Mesohaline Tidal Chesapeake Bay Segment is Use II – Support of Estuarine and Marine Aquatic Life and Shellfish Harvesting. The Maryland Department of the Environment (MDE) has identified the Patapsco River Mesohaline Tidal Chesapeake Bay Segment (Integrated Report Assessment Unit ID: PATMH) Tidal Chesapeake Bay Segment on the State’s 2012 Integrated Report as impaired by sediments (1996), nutrients (1996), bacteria (1998), polychlorinated biphenyls (PCBs, 1998), various metals (1998), impacts to biological communities (2002), debris/floatables/trash (2008), and various metals (chromium in sediments , lead [Pb] in sediments , zinc [Zn] in sediments ).
The nutrient listings for the PATMH Tidal Chesapeake Bay Segment and Baltimore Harbor have been addressed through a TMDL approved by EPA on December 17, 2007. The Chesapeake Bay TMDL, which was approved by the EPA on December 29, 2010, has also addressed the nutrient listings for the PATMH Tidal Chesapeake Bay Segment and is currently under reevaluation to determine whether previously developed TMDLs would be superseded by the corresponding Bay TMDL. The sediment listing for the PATMH Tidal Chesapeake Bay Segment has also been addressed via the Chesapeake Bay TMDL. The trash listings for the Middle Branch and Northwest Branch portions of the PATMH Tidal Chesapeake Bay Segment will be addressed through a TMDL currently under development. The listing for impacts to biological communities in the PATMH Tidal Chesapeake Bay Segment will be addressed separately at a future date. The listing for chlordane in Baltimore Harbor has been addressed through a TMDL approved by EPA on March 23, 2001. The listings for PCBs in Bear Creek and Baltimore Harbor have been addressed through a TMDL submitted to EPA on September 30, 2011. The listings for Pb, Zn, and enteroccocus in the Northwest Branch and Zn in Bear Creek will be addressed separately at a future date. This WQA will address the 1998 chromium listings for Northwest Branch and Bear Creek, for which a data solicitation has been conducted, and all readily available data from the past five years have been considered.
Barring the receipt of contradictory data, the report available below, will be used to support a revision of the chromium listing for the Baltimore Harbor, Northwest Branch, and Bear Creek portions of the Patapsco River Mesohaline Tidal Chesapeake Bay Segment watershed, from Category 5 (“waterbody is impaired, does not attain the water quality standard, and a TMDL is required”) to Category 2 (“waterbodies meeting some [in this case chromium-related] water quality standards, but with insufficient data to assess all impairments”) when MDE proposes the revision of the Integrated Report. Although this WQA does not support the continued Category 5 listing of this watershed for chromium impairment, the State reserves the right to require future controls if evidence suggests chromium impairments in the future.
Water Quality Analysis (WQA) of Chromium in Northwest Branch and Bear Creek Portions of the Patapsco River Mesohaline Tidal Chesapeake Bay Segment, Baltimore City and Baltimore County, Maryland
(Approved on June 24, 2014)
Comment Response Document
Additional Supporting Information
2004 WQA Main Report Main Report
2004 WQA Comment Response Document
Bioassay Testing of Baltimore Harbor Sediments Spiked with Cr(VI) Final Report
Please direct questions or comments concerning this project to Maryland's TMDL Program at (410) 537-3818.
1800 Washington Boulevard, Baltimore, MD 21230