It noted the reason for that concern: “Millions of people live in areas where their drinking water resources are located near hydraulically fractured wells. While most hydraulic fracturing activity from 2000 to 2013 did not occur in close proximity to public water supplies, a sizeable number of hydraulically fractured wells (21,900) were located within 1 mile of at least one PWS source (e.g., infiltration galleries, intakes, reservoirs, springs and ground water wells). Approximately 6,800 sources of drinking water for public water systems, serving more than 8.6 million people year-round, were located within 1 mile of at least one hydraulically fractured well. An additional 3.6 million people obtain drinking water from private water systems.”