In January 1997, Onondaga County executed an Amended Consent Judgment (ACJ) in settlement of litigation initiated in connection with alleged violations of state and federal water pollution control requirements. The ACJ obligated the Onondaga County to perform a nonpoint source (NPS) environmental benefit project (EPB) in the Onondaga Lake watershed. The EBP is a demonstration project where best management practices (BMPs) are being implemented on three farms and at two urban sites in the Onondaga Lake watershed. The major objective of the demonstration project is to document water quality before and after BMP implementations. Agricultural pre-BMP water quality data were collected during the period, July 1999 to June 2000. Water quality samples were taken upstream and downstream of the farms once per month during rain events. Agricultural and urban BMP selection and design occurred during the period, July 1999 to June 2000. Construction occurred during the summer and fall of 2000. Post-BMP water quality sampling began in November 2000, and will continue until the spring of 2002. When the post-BMP water quality sampling is complete, the pre- and post- data will be compared. The goal of these analyses is to provide a first order estimate of agricultural BMP effectiveness, and to relate these findings to other pollutant sources throughout the watershed. This demonstration project is scheduled to be completed by May 2002. A final report will document the effectiveness of these BMPs to improve water quality. In addition BMP stability, longevity, and operation and maintenance issues will be documented. Ultimately these data and results will aid County officials in making decisions regarding the costs and benefits of nonpoint BMP implementation and associated water quality improvements.