Colorado’s new rules requiring groundwater sampling both prior to and following oil and gas development will become effective May 1, 2013.  The rules, promulgated by the Colorado Oil and Gas Conservation Commission, establish required procedures for oil and gas operator baseline testing of groundwater, and post completion groundwater sampling in order to monitor the impact of each well requiring the submission of a Form 2 Application for Permit to Drill on or after May 1, 2013.