Opinion ID: 1438955
Heading Depth: 2
Heading Rank: 2

Heading: Discovery of Methane

Text: On September 24, 1987, following the construction of various streets and approximately forty-five homes, the local fire department and the State Emergency Response Team were called to the development to investigate an apparent flash ignition that occurred in the sump of a home located on Jonathan Drive. Thereafter, the Delaware Department of Natural Resources and Environmental Control (DNREC) and the United States Environmental Protection Agency (EPA) commenced an investigation to determine the cause and source of the flash ignition. Tests revealed that the flash ignition was caused by methane gas, which was detected in several of the Raintree homes at a concentration of one-hundred percent of the lower explosive limit (LEL). [2] In response, ventilation systems were installed in the affected homes to prevent gas buildups and explosions. Additional tests revealed that the debris buried in the DP & L right-of-way was the source of the methane gas. Methane is a naturally occurring gas that is created by the decomposition of organic material, such as tree stumps and limbs, in a moist, anaerobic environment. [3] As the organic material is digested by micro-organisms, methane is produced as a by-product. In the present case, the methane gas travelled laterally through the ground, rather than dissipating into the atmosphere because the trenches were capped with soil containing a high clay content. The Board found that sewage from an old sewage line had seeped from the line and interacted with the construction waste. The sewage did not cause the breakdown of the construction waste into methane, but it merely increased the rate at which the process occurred. According to these findings, the construction waste would have decomposed into methane gas and created the hazardous situation regardless of the presence of the sewage, but the sewage caused the decomposition to happen more rapidly.