Section 303(d) of the federal Clean Water Act (the Act) directs States to identify and list waters, known as water quality limited segments (WQLSs), in which current required controls of a specified substance are inadequate to achieve water quality standards. For each WQLS, the State is to either establish a Total Maximum Daily Load (TMDL) of the specified substance that the waterbody can receive without violating water quality standards, or provide justification for removal from the 303(d) list. The Youghiogheny River was identified on the States 1996 list of WQLSs as impaired by nutrients, among other substances. The Youghiogheny River is a freshwater stream traversing mountainous Garrett County in the western part of Maryland. It is a tributary of the Mononghela River that merges into the Ohio River. It starts in Maryland then flows north into West Virginia then back into Maryland and Pennsylvania before merging into the Mononghela River in Pennsylvania about 66 miles from the Maryland border.