Reading the urban landscape: Clues to gas leak damage to vegetation

Background/Question/Methods

Natural gas serves approximately 65 million homes; 5 million businesses like hotels, restaurants, hospitals, schools and supermarkets; 193,000 factories; and 5,500 electric generating units. On a daily basis, the average U.S. home uses more than 200 cubic feet of natural gas

There are nearly 2.4 million miles of pipeline of varying sizes and pressures that transport natural gas from the natural gas wellhead to more than 177 million Americans throughout the U.S.

Natural gas is naturally colorless and odorless. Mercaptan, which some describe as having the smell of rotten eggs, is added to natural gas to make it easier to detect a leak. Instrumentation can detect many gas leaks but by observing the urban environment, many more leaks can be detected that may be damaging the urban landscape. Reading the urban landscape can also give us information as to the location of pipelines and other subsurface utilities that can be affected by leaking natural gas.

Results/Conclusions

Ganoderma (fungus), black soil, insects and dead or dying vegetation are some of the bio-indicators of subsurface pipeline problems.  By observing public utility structures such as water gate valves, sewer manholes, communications manholes, electrical structures and storm drains, we can often determine the location of natural gas pipelines and the extent of natural gas leaks. Natural gas leak surveys conducted in the greater Boston area have identified thousands of trees with natural gas within their root zones, resulting in substantial losses to the urban forests.