A consensus has recently been reached by state regulators, some energy companies, academics, and environmentalists that natural gas drilling has led to several incidents of water pollution; this is not due to fracking, which is a common method used for oil and natural gas extraction. Instead, wells that have been improperly or poorly built is a contributing factor to some water contamination cases. In instances like these, the wells were not accurately sealed with subterranean cement, and as a result, causing contaminants to travel from the underground up the well bore and into shallow aquifers that provide drinking water.