Oceanborne container activities at U.S. seaports, while essential for trade and commerce, can affect water quality, air quality, and land-use patterns. The complex interconnections between port activities and environmental quality have implications for the nation's coastal, ocean, and freshwater resources. They also affect transportation demands and traffic congestion. U.S. ports have recently renewed their attention to environmental concerns. In particular, port and federal agencies with responsibility for marine environmental quality have focused on the following issues:
U.S. ports are also considering the potential environmental challenges implicit in climate change, including costs of improved infrastructure to protect harbors from rising sea levels, increased port maintenance costs, and increased operations costs due to delays in shipping activities (EPA 2008b).
To deal with these challenges, the U.S. Environmental Protection Agency (EPA) has introduced new environmental and sustainability initiatives. EPA's initiative to reduce diesel emissions at U.S. ports, called Clean Ports USA, suggests a variety of operational and technological ideas that ports can adapt to their individual needs, including truck idle reduction, the use of cleaner fuel, and replacement of older equipment (EPA 2005). EPA has also developed an overarching strategy for sustainable ports that provides measures that ports can implement, largely voluntarily, in partnership with the agency. Focus areas include clean air and affordable energy, clean and safe water, healthy communities and ecosystems, the global environment, ports communication, and enforcement (EPA 2007).
By 2008, more than 18 U.S. ports were developing and using Environmental Management Systems (EMS), which integrate environmental considerations in both day-to-day operational decisions and long-term planning (EPA 2008a). Many U.S. ports have also launched their own "green" initiatives. For example, the ports of Los Angeles and Long Beach have received national attention for environmental efforts focused on air quality. With help from California state and local air-quality agencies, for example, they are using cleaner fuels and replacing older trucks with hybrid vehicles, including the world's first hybrid tugboat (Murr 2008).
16 Ballast water is taken on empty ships to stabalize the ship. When a ship is loaded with cargo, the ballast water is pumped out, introducing aquatic organisms from its origin port at its destination.