The Texas Railroad Commission, which regulates the state's oil and gas industry, was quick to dismiss the study as arbitrary, Kuchment writes. "In November 2014 the commission tightened its rules for disposal wells. Since then, it has received 51 disposal-well applications. Of these, 22 permits were issued with special conditions, such as requirements to reduce daily maximum injection volumes and pressure and to record volumes and pressures daily as opposed to monthly. Nine permits were issued without special conditions. The rest were either withdrawn, returned to the applicant for more information, protested and sent to a hearing, or are still pending."
The study links man-made earthquakes back to the early days of the oil and gas industry, Kuchment writes. "The first man-made quake struck in 1925 in the Goose Creek oil field along the Gulf Coast east of Houston. Humble Oil, a precursor of Exxon, had extracted so much oil that the ground sank and caused houses to shake and dishes to crash to the floor. Over the years, different petroleum production methods have triggered quakes, including oil and gas extraction and enhanced recovery, in which operators pump water or carbon dioxide into reservoirs to boost the flow of oil. Each method can, in rare cases, raise or lower pressure on faults and cause them to rupture."