Water Quality Analyses (WQA) with EPA Concurrence of MDE's Findings: Little Seneca Lake

Little Seneca Lake lies in the Piedmont ecoregion, located between the Appalachian Mountains and the Atlantic Coastal Plain on the East Coast. Inflow to the lake is from three major river channels: Tenmile Creek, Cabin Branch Creek, and Little Seneca Creek.  The lake discharges to Little Seneca Creek, which in turn discharges to the Great Seneca River.

Little Seneca Lake (in the Seneca Creek watershed, basin code 02140208) was identified on the 1998 303(d) list, submitted to EPA by the Maryland Department of the Environment (MDE), as being impaired by nutrients.

The report available below provides an analysis of recent monitoring data to address whether or not the watershed is still impaired by nutrients. An analysis of recent monitoring data shows that the criteria associated with nutrients are being met, and the designated use in Little Seneca Lake is supported. This analysis supports the conclusion that in this case a TMDL for nutrients is not necessary to achieve water quality. The WQA will be used to support the nutrient listing change for Little Seneca Lake from Category 5 (“waterbodies impaired by one or more pollutants and requiring a TMDL”) to Category 2 (“surface waters that are meeting some standards and have insufficient information to determine attainment of other standards”) when MDE proposes the revision of Maryland’s 303(d) list for public review in the future.

Although the waters of Little Seneca Lake do not display signs of eutrophication, the State reserves the right to require future controls in the Little Seneca Lake watershed if evidence suggests nutrients from the basin are contributing to water quality problems. 

WQA of Eutrophication for
Little Seneca Lake, Montgomery County, Maryland

(EPA Concurrence: August 19, 2006)

EPA's Decision Letter EPA's Decision Letter

Main Report 

WQA_Little_Seneca_Lake_Eutro.pdf (1660 KB)

Comment Response Document

CRD_Little_Seneca_Lake_Eutro.pdf (13 KB)


Contact Information

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