The Toronto Port Authority's main purpose and function is to operate the Port of Toronto. The TPA also operates the Toronto City Centre Airport and the Outer Harbour Marina. Activities and powers of the TPA include: development, application, enforcement and amendment of rules, orders, bylaws, practices or procedures relating to the use, occupancy or operation of the port; administration of fees or charges as authorized by the Canada Marine Act; management, leasing or licensing of the federal real property as described in the TPA's letters patent; construction, establishment, repair, maintenance, operation, removal, or demolition of port-related infrastructure; provision of services to port users, such as: environmental assessment, dredging and dredgeate disposal, navigational aids, stevedoring services, emergency planning and response, multi-modal facilities and services, salvage and seizure, warehousing and security services.