Horizontal hydraulic fracturing, or "fracking" for short, is a new kind of extraction process for methane (natural gas) that goes deeper than vertical drilling. It is only a decade old. It is a technique of "expanding or creating rock fractures leading from substantially horizontal wellbores, by injecting substances including but not limited to water, fluids, chemicals, and proppants, under pressure, into or under rock formations, for the purposes of exploration, drilling, completion, or production of oil and gas." Chemicals include toxins, carcinogens and endocrine disruptors and many of the chemical components are secret and kept from the public. Fracking uses millions of gallons of water and produces many millions of gallons of frack wastes.
For more information about fracking in Michigan, see www.banmichiganfracking.org.