The Primary Trunk Sewer is comprised of approximately 5km of 3m diameter reinforced concrete pipe and cast in place concrete tunnel which conveys all wastewater generated in the York‐Durham Sewage System service area to the Duffin Creek WPCP, a secondary wastewater treatment facility. The two facilities service 1.2m residents and are jointly owned by York Region and Durham Region. This presentation will present the approach to developing a detailed facility AMP and the range of data, methods and tools that were employed. It will include levels of service, risk assessment of existing deficiencies, statistical models of long term renewals, operational maintenance optimization, growth and energy efficiency strategies and the integration with financial planning and budgeting.