Water Quality Analyses (WQA) with EPA Concurrence of MDE's Findings: Lower Gunpowder Falls

The Lower Gunpowder Falls watershed is located in the Upper Western Shore region of the Chesapeake Bay watershed within Maryland.  The watershed covers a portion of Baltimore County. 

The Lower Gunpowder Falls (basin code 02130802) was first identified on the 1996 303(d) list submitted to EPA by the Maryland Department of the Environment (MDE) as impaired by heavy metals and nutrients, with biological impairment added to the list in 2002.  All impairments are listed for the non-tidal streams.  The initial listing for heavy metals was questionable because:  1) no specific pollutants were defined; 2) the original listing was based on total recoverable metals (current standard is based on dissolved metals); 3) inappropriate sampling techniques were applied (lack of filtration); 4) supporting data needed to interpret criteria was not available (hardness); and 5) a default hardness of 100 mg/L was used to convert and relate the total recoverable metals to the dissolved criteria, which superceded the total recoverable metals criteria. Awater quality analysis (WQA) of heavy metals for Lower Gunpowder Falls was performed using recent water column data.  Results show no impairment for heavy metals.  The nutrient and biological impairments will be addressed separately at a future date. 

WQA of Heavy Metals for the Lower Gunpowder Falls,
Baltimore County, MD

(Concurrence November 10, 2003)

EPA's Decision Letter EPA's Decision Letter
Main Report  WQA_lowergunpowder_metals.pdf

Comment Response Document


Contact Information

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