Total Maximum Daily Load (TMDL) analysis was completed for Eagleville Brook, Mansfield, Connecticut. Eagleville Brook was included on the 2004 List of Connecticut Waterbodies Not Meeting Water Quality Standards 1 (2004 List) due to exceedences of the aquatic life criteria contained within Connecticut's Water Quality Standards (WQS) 2. Under section 303(d) of the Federal Clean Water Act (CWA), states are required to develop TMDLs for waters impaired by pollutants for which technology-based controls are insufficient to achieve water quality standards. The TMDL represents the maximum loading that a waterbody can receive without exceeding water quality criteria which have been adopted into the WQS. Since the cause of the impairment in Eagleville Brook was unknown at the beginning of this investigation, a Stressor Identification (SI) analysis was completed to determine the most probable cause of the impairment. The SI determined that a complex array of pollutants transported by stormwater was the most probable cause of the impairment. The TMDL was developed using Impervious Cover (IC) as a surrogate parameter for a mix of pollutants conveyed by stormwater. The TMDL is established as the percent of impervious cover (% IC) throughout the watershed that must be achieved to meet the aquatic life criteria and attain the designated aquatic life uses. Federal regulations require that the TMDL analysis identify the portion of the total loading which is allocated to point source discharges (termed the Wasteload Allocation or WLA) and the portion attributed to nonpoint sources (termed the Load Allocation or LA), which contribute that pollutant to the waterbody. In this case, the WLA and LA are expressed in terms of % IC, again as a surrogate for the mix of pollutants conveyed by stormwater. In addition, TMDLs must include a Margin of Safety (MOS) to account for uncertainty in establishing the relationship between pollutant loadings and water quality.