This document establishes Total Maximum Daily Loads (TMDLs) that addresses the control of pollutants affecting dissolved oxygen levels in Antietam Creek. The water quality goal of the TMDLs documented here is to establish allowable carbonaceous biochemical oxygen demand (CBOD) and nitrogenous biochemical oxygen demand (NBOD) inputs at a level that will ensure the maintenance of the dissolved oxygen standard. Antietam Creek, a tributary of the Potomac River, is a free-flowing freshwater stream. As such, the TMDLs were developed using a mathematical model for free-flowing streams. CBOD and NBOD contributions from the nonpoint and point sources primarily affect the dissolved oxygen in the Antietam Creek; therefore, the model was used to determine allowable CBOD and NBOD loadings that will meet the dissolved oxygen standard. Load allocations were determined for distributing allowable loads between point and nonpoint sources. The model was also used to investigate seasonal variations in stream conditions and to establish margins of safety that are environmentally conservative.