Final TMDL Approved by EPA: Piscataway Creek and Mattawoman Creek

The Piscataway Creek and Mattawoman Creek tidal segments are tributaries of the Tidal Potomac River which drain portions of Prince George’s and Charles Counties.  The Potomac River extends for 117 miles (188 kilometers [km]) from its mouth at Pt. Lookout in St. Mary’s County to its head-of-tide located approximately 0.4 miles (0.64 km) upstream of Chain Bridge in the District of Columbia.   ​The Piscataway Creek and Mattawoman Creek watershed areas are 180 square kilometers (km2) and 251 km2, respectively.
 
The Maryland Department of the Environment (MDE) has identified the waters of the Piscataway Creek and Mattawoman Creek tidal segments on the State's 2016 Integrated Report (IR) of Surface Water Quality as impaired for multiple pollutants including sediments, chlorides, sulfates, polychlorinated biphenyls (PCBs), metals and nutrients. These waterbodies are associated with two assessment units in Maryland IR: a non-tidal 8-digit watershed and an estuarine portions. For more information about the listings, please see the TMDL report.
 
The report available below, established TMDLs for the Piscataway Creek and Mattawoman Creek tidal segments based on modeling from the 2007 TMDL of PCBs for Tidal Portions of the Potomac and Anacostia Rivers (TPAR TMDL). The TPAR TMDL model included the Piscataway Creek and Mattawoman Creek tidal segments; however, these waters did not receive individual TMDLs as they were not listed as impaired in Maryland’s IR at the time of the TPAR TMDL.  In establishing the individual TMDLs, the report demonstrates that the allocations assigned in the TPAR TMDL will result in the attainment of water quality standards in the Piscataway Creek and Mattawoman Creek tidal segments. 
 

Total Maximum Daily Load of Polychlorinated Biphenyls in the Piscataway Creek and Mattawoman Creek Tidal Fresh Chesapeake Bay Segments, Prince George's and Charles Counties, MD

(Approved on February 19, 2019)

EPA's Decision Letter EPA's Decision Letter (11,938 KB)
Main Report

Piscataway_Mattawoman_PCB_TMDL_final.pdf (1,699KB)

Comment Response Document Piscataway_Mattawoman_PCB_TMDL_CRD.pdf (120KB)

Additional Supporting Information

Facts about PCBs​

Tidal Potomac and Anacostia River PCB TMDL

 

Contact Information

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