TMDL_Final_BaltHarbor_PCBs

Final TMDLs Approved by EPA: Baltimore Harbor

The Patapsco River Mesohaline Chesapeake Bay Segment is a tidal estuary, or embayment, located on the western shore of the Chesapeake Bay. The total watershed draining to the Bay Segment covers 1,514 square kilometers (km2) (374,040 acres) and spans Baltimore City, Carroll, Howard, Anne Arundel, and Baltimore Counties. The Baltimore Harbor Maryland 8-Digit (MD 8-Digit) watershed comprises the majority of the Patapsco River Mesohaline Chesapeake Bay Segment (referred to as the Baltimore Harbor embayment). Curtis Creek/Bay and Bear Creek are specific segments within the Baltimore Harbor embayment. Curtis Creek/Bay is located on the southwest shore of the Harbor within both Baltimore City and Anne Arundel County, while Bear Creek is located on the northwest shore of the Harbor within solely Baltimore County. The total watershed area draining to the Baltimore Harbor portion of the Bay Segment covers 1,491 km 2 (368,388 acres); however, the direct drainage portion of this watershed area only covers 219 km2 (53,994 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, Curtis Creek/Bay, 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) on the State’s Integrated Report as impaired by nutrients – nitrogen and phosphorus (1996), sediments (1996), trash and debris (2008), and impacts to biological communities (2004). The Baltimore Harbor portion of the Patapsco River Mesohaline Tidal Chesapeake Bay Segment (Integrated Report assessment unit ID: MD-PATMH-02130903) has been individually identified on the State’s Integrated Report as impaired by Polychlorinated Biphenyls (PCBs) PCBs in fish tissue (1998), chlordane (1998), bacteria – Furnace Creek, Marley Creek, Rock Creek, and all tidal waters upstream of the harbor tunnel (1998), zinc – Middle and Northwest Branches (1998), chromium – Northwest Branch (1998), and lead - Northwest Branch (1998). In addition, the Curtis Creek/Bay portion of the Patapsco River Mesohaline Tidal Chesapeake Bay Segment (Integrated Report assessment unit ID: MD-PATMH-CURTIS_BAY_CREEK) has been individually identified on the State’s Integrated Report as impaired by PCBs in both fish tissue and sediment (1998) and zinc (1998), and the Bear Creek portion of the Bay Segment has been individually identified on the State’s Integrated Report (Integrated Report assessment unit ID: MD-PATMH-BEAR_CREEK) as impaired by PCBs in both fish tissue and sediment (1998), zinc (1998), and chromium (1998). 

Bacteria TMDLs for the Marley and Furnace Creeks within the Baltimore Harbor embayment were submitted to the EPA in 2010. The bacteria impairment for Rock Creek within the Baltimore Harbor embayment was delisted in 2004. Chlordane and nutrient (nitrogen and phosphorus) TMDLs for the Baltimore Harbor embayment were approved by the EPA in 2001 and 2007, respectively. Then, in 2010, the Chesapeake Bay nutrient and sediment TMDLs were developed by the EPA, which addressed the nutrient and sediment impairment listings for the entirety of the Patapsco River Mesohaline Tidal Chesapeake Bay Segment. WQAs for the chromium, lead, and zinc impairment listings in the Northwest Branch of the Baltimore Harbor embayment, the zinc impairment listing in the Middle Branch of the Baltimore Harbor embayment, the zinc impairment listing in the Curtis Creek/Bay, and the zinc and chromium impairment listings in Bear Creek were developed by MDE in 2004; however, they were not approved by EPA, as the information to support the delisting was insufficient at the time. Studies are currently underway to determine whether these metals listings will require TMDLs to be developed in the future. The listing for impacts to biological communities, trash, and bacteria upstream of the harbor tunnel will be addressed at a future date. The document, available below, establishes total PCB (tPCB) TMDLs for the Baltimore Harbor embayment, Curtis Creek/Bay, and Bear Creek, for which a data solicitation was conducted, and all readily available data from the past 5 years have been considered. 

 

Total Maximum Daily Loads of Polychlorinated Biphenyls in the Baltimore Harbor, Curtis Creek/Bay, and Bear Creek Portions of the Patapsco River Mesohaline Tidal Chesapeake Bay Segment, Maryland

(Approved on October 1, 2012)

EPA's Decision Letter EPA's Decision Letter
(Does not include MDE's requested revisions)
MDE's Edits to EPA's Decision Letter MDE's Decision Letter Edits
Main Report

BaltHarbor_PCBs_tmdl_092811_Final.pdf (13,035KB)

Comment Response Document

BaltHarbor_PCBs_tmdl_092911_CRD_Final.pdf (36KB)


Contact Information

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

 

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