Methane is a naturally occurring hydrocarbon gas that can exist underground. It is lighter than air, colorless, odorless and flammable. It is found in shallow organic rich deposits and deep coal beds as well as other rock units. Underground methane can be influenced by the coal mining process. Prior to mining, the longwall operators vent water wells and install gas detectors in the houses that are within or proximal to the longwall panels. If a homeowner believes that undermining is causing a methane problem on their property, they report this to the mine operator. The operator will report the claim to the Department. If the operator accepts responsibility, they will fix the problem by venting the gas to the atmosphere and providing the homeowner with gas detectors for their structures. If the operator denies responsibility, the Department will investigate to determine cause. If the Department finds the operator responsible, the operator will be ordered to mitigate the gas problem. If the Department investigation finds the methane release was not caused by mining, the owner has the right to file an appeal with the PA Environmental Hearing Board.
In rare cases, methane can find its way into a structure via cracks in the foundation and/or basement floor. Sometimes this can be mitigated with a system that creates either positive or negative pressure in the basement which keeps the methane in check. This type of system is not always successful at mitigating the stray gas. In those situations, the coal company may purchase an effected dwelling.
Methane cases are rarely reported to the Department. Stray gas problems are typically tied to an incident of structure damage. A long period from notification to solutions may be a result of additional monitoring, perhaps several seasons, that is needed to assess the problem or to continue monitoring during the mining of additional panels. Mitigation plans can take additional time to ascertain if they are working and may be delayed by related repairs to the structure.
Last updated 11/29/2021