Last Updated on 2008-08-26 00:00:00
The term ‘brownfield’ is used to refer to both known contaminated sites and those only suspected of being so because of previous land-use activities (e.g. waste disposal, manufacturing, petrol stations). Below are two examples of brownfield definitions:
‘Brownfields are sites that have been affected by the former uses of the site and surrounding land; are derelict or underused; have real or perceived contamination problems; are mainly in developed urban areas; and require intervention to bring them back to beneficial use.’
‘A brownfield site is any land or premises which has previously been used or developed and is not currently fully in use, although it may be partially occupied or utilized. It may also be vacant, derelict or contaminated. Therefore a brownfield site is not available for immediate use with intervention.’
Brownfield regeneration is attractive to... More »
Exxon Valdez Oil Spill
Last Updated on 2008-08-26 00:00:00
On March 24, 1989, the tanker Exxon Valdez, en route from Valdez, Alaska to Los Angeles, California, ran aground on Bligh Reef in Prince William Sound, Alaska. The vessel was traveling outside normal shipping lanes in an attempt to avoid ice. Within six hours of the grounding, the Exxon Valdez spilled approximately 10.9 million gallons of its 53 million gallon cargo of Prudhoe Bay crude oil. Eight of the eleven tanks on board were damaged. The oil would eventually impact over 1,100 miles of non-continuous coastline in Alaska, making the Exxon Valdez the largest oil spill to date in U.S. waters.
The response to the Exxon Valdez involved more personnel and equipment over a longer period of time than did any other spill in U.S. history. Logistical problems in providing fuel, meals, berthing, response equipment, waste management and other resources were one of the largest challenges to... More »
Nonpoint Source Pollution
Last Updated on 2008-08-22 00:00:00
Nonpoint source pollution is difficult to control because it comes from many different sources and locations. (Source: NOAA)
Most nonpoint source pollution occurs as a result of runoff. When rain or melted snow moves over and through the ground, the water absorbs and assimilates any pollutants it comes into contact with. Following a heavy rainstorm, for example, water will flow across a parking lot and pick up... More »
Clean Water Act, United States
Last Updated on 2008-07-21 00:00:00
ncreasing public interest in protecting America’s waters from pollution pushed Congress to enact the Federal Water Pollution Control Act, popularly known as the Clean Water Act (CWA), in 1972. As amended in 1977, this law became commonly known as the Clean Water Act. The Act established the basic structure for regulating discharges of pollutants into the waters of the United States. Its principle intent was to ". . .restore and maintain the chemical, physical, and biological integrity of the Nation's waters" (Section 101). To accomplish that objective, the act aimed to attain a level of water quality that "provides for the protection and propagation of fish, shellfish, and wildlife, and provides for recreation in and on the water" by 1983 and to eliminate the discharge of pollutants into navigable waters by 1985.
The CWA gave the Environmental Protection Agency (EPA) the authority to... More »
Impacts of Air Pollution on Local to Global Scale
Last Updated on 2008-06-19 00:00:00
Air pollution is somewhat difficult to define because many air pollutants, at low concentrations, are essential nutrients for the sustainable development of ecosystems. So, air pollution could be defined as: A state of the atmosphere, which leads to the exposure of human beings and/or ecosystems to such high levels or loads of specific compounds or mixtures thereof, that damage is caused. With very few exceptions, all compounds that are considered air pollutants have both natural as well as human-made origins.
Air pollution is not a new phenomenon; in Medieval times, the burning of coal was forbidden in London while Parliament was in session. Air pollution problems have dramatically increased in intensity as well as scale due to the increase in emissions since the Industrial Revolution.
All reports on air pollution in the nineteenth and early twentieth centuries indicate that the... More »