The Colorado Oil and Gas Conservation said new rules require operators to sample nearby water wells before and after drilling campaigns in order to provide assurances that water supplies aren't impacted by energy development.
"This rule represents a strong, proactive step to monitor and protect our groundwater and is right for Colorado," said Commissioner Andy Spielman in a statement. "We have once again set the bar high in our assertive and judicious regulatory approach to oil and gas development."
The state government said operators need to sample up to four water wells within a half of a mile of new oil and natural gas wells before drilling operations begin. Two more samples are required within a year and then again within six years.
The U.S. Energy Department said oil production from Colorado accounts for about 1 percent of the national output. Natural gas production from conventional and unconventional plays in Colorado account for more than 5 percent of the national total.
Some of the chemicals used in the extraction of unconventional reserves like shale pose a potential threat to groundwater supplies. The Colorado government says no other state in the nation requires post-drilling water sampling.