McMurdo Station has attempted to improve environmental management and waste removal in order to adhere to the Protocol on Environmental Protection to the Antarctic Treaty, signed on October 4, 1991, which entered into force on January 14, 1998. This agreement prevents development and provides for the protection of the Antarctic environment through five specific annexes on marine pollution, fauna and flora, environmental impact assessments, waste management, and protected areas. It prohibits all activities relating to mineral resources except scientific. A new waste-treatment facility was built at McMurdo in 2003. Three Enercon E-33 (330 kW each) wind turbines were deployed in 2009 to power McMurdo and New Zealand's Scott Base, reducing diesel consumption by 11% or 463,000 litres per year. McMurdo Station (nicknamed "Mac-Town" by its residents) continues to operate as the hub for American activities on the Antarctic continent.