Fracking fluids

From rural Pennsylvania to Los Angeles, more than 17 million Americans live within a mile of at least one oil or gas well. Since 2014, most new oil and gas wells have been fracked. Fracking, short for hydraulic fracturing, is a process in which workers inject fluids underground under high pressure. The fluids fracture coal beds and shale rock, allowing the gas and oil trapped within the rock to rise to the surface. Advances in fracking launched a huge expansion of U.S. oil and gas production starting in the early 2000s but also triggered intense debate over its health and environmental impacts. Fracking fluids are up to 97% water, but they also contain a host of chemicals that perform functions such as dissolving minerals and killing bacteria. The U.S. Environmental Protection Agency classifies a number of these chemicals as toxic or potentially toxic. The Safe Drinking Water Act, enacted in 1974, regulates underground injection of chemicals that can threaten drinking water...