Monitoring of air contaminants is used to establish community exposure, to evaluate dispersion model performance, to test the adequacy of emission inventories, to establish regulatory compliance, and to provide feedback to operators in forecast-based control systems. CEMC has been involved in the design, implementation, testing, utilization and management of networks for both industry directed and community directed goals. We have conducted the design, evaluation, and utilization of networks for clients like Noranda Horne and Gaspé; Montreal East Industrial area; Vale Inco and Falconbridge in Sudbury and Timmins; Nanticoke; Hamilton; Syncrude in the Tar Sands, Algoma Ore in Wawa, Essar Steel in Sault Ste Marie, Irving Oil in Saint John and Tonolli in Mississauga. CEMC has also implemented operations control directed networks for Vale Inco and Falconbridge in Sudbury, Noranda Horne and Gaspé, and Algoma Wawa.