The webinar will describe the history of emissions controls employed on biogas (e.g., landfill gas, digester gas, etc.) engines that are used in renewable energy projects.  It will include a summary of the evolution of these controls over the last 20 years and cover the regulatory requirements that have affected these controls, including determinations of BACT or LAER.  The webinar will include case studies where these controls were employed.  The audience for this webinar would include consultants in the air quality field, vendors of emissions control technologies, engine plant owner/operators, air regulators, and renewable energy project developers.