With the realization that construction of a highway can result in additional un-permitted impacts to natural resources and that environmental commitments made by the Department are not always implemented, the Army Corps of Engineers requires the Pennsylvania Department of Transportation to contract an independent environmental compliance monitor for large projects. The responsibilities of the environmental compliance monitor are to ensure that impacts to natural resources are minimized, additional un-permitted impacts do not occur, and documented environmental commitments are implemented. For past transportation projects, environmental compliance monitoring was strictly based on erosion and sedimentation control monitoring. The compliance monitor was often viewed as an antagonist to the project and input was ignored if it conflicted with the project schedule or resulted in additional construction cost. Expansion of the monitors responsibilities to include environmental compliance monitoring presented the task of meshing monitoring responsibilities and implementing a monitoring program that is viewed by highway contractors and construction managers as an integral component of the overall project. The Pennsylvania Department of Transportation, I-99, Route 220 Improvements Project provides a case study in implementing an effective environmental compliance monitoring program. Principal components of the monitoring program include environmental final design review, environmental sensitivity training for contractors, established hierarchy of communication, complaint inquiry/resolution procedures, on going agency coordination, and Departmental support. The Route 220 environmental compliance-monitoring program resulted in the resolution of conflicts between environmental compliance monitoring and construction through developing a team concept. At the core of the team concept approach was the premise that all parties respect the responsibilities and roles of each member and that the focal point of the project was environmentally based. This environmental monitoring approach to highway construction has not only resulted in minimizing additional impacts to permitted resources but has eliminated impacts to un-permitted natural resources. In addition the monitoring procedure has kept the project in compliance with permit conditions and environmental commitments.