Hydraulic fracturing, also known as hydrofracking, involves injecting sand, water and chemicals into drilled wells at high pressure to extract natural gas from shale rock formations deep underground. While hydrofracking may increase the domestic supply of natural gas, it can contaminate drinking water sources if the fracking fluids and methane gas leak into the groundwater. Local officials are concerned about potential hydrofracking in their region contaminating the watershed that supplies drinking water to over 9 million people. The mayor of Little Falls, NY opposes hydrofracking in his city in order to protect the "sacred" watershed as the region prepares for possible natural gas drilling.