After World War II automobile sales soared and, as a result, there was also a large increase in gas stations to keep up with peoples desires to travel longer and longer distances. Gasoline was stored underground in massive steel tanks that were not resistant to corrosion. These underground storage tanks, were only meant to last thirty to fifty years but have continued to stay buried for much longer and have been leaking harmful chemicals into the earth surrounding them since the 1980s.
Leaks are often slow but once the gasoline escapes from inside, it will move through the soil and float atop the groundwater supply. The gasoline will then begin to vaporize and be able to be detected at ground level. Almost fifty percent of all Americans get their drinking water from underground sources and contamination due to these leaking tanks poses a serious threat to many communities.
Nearly 400,000 underground storage tank sites requiring remediation had been identified by 2001. Clean up is necessary, as the chemicals leaking into the soil and water supplies pose serious human health concerns. The most harmful of these chemicals present in gasoline is benzene, which poses the risk of cancer when water containing the substance is used for drinking or bathing. A second harmful component is methyl tertiary butyl ether, or MTBE, which is added to gasoline in order to make it burn cleaner. MTBE is also known to cause cancer and many states have begun to stop using it as a gasoline additive. In addition to health concerns, there is also a threat of fire when vapors make their way through sewage lines and into buildings.
Solving this issue usually relies on removing the leaking tanks, the surrounding contaminated soil, and the harmful components present in the groundwater. This process can take many years to accomplish. Unfortunately for some extreme cases, reversal of the contamination is not possible and the effected communities have had to resort to other water supplies.
Funding for storage tank removal in the United States commonly comes from state licensing fees on gasoline and from EPA grants. Modern day tanks are subject to EPA standards that must be corrosion resistant and be equipped with advanced leak detection.
Nearly 1.5 million tanks have already been closed but there is still a lot more work to be done since the number of these sites in need remediation is not known.
Added by Will Baker