CHARACTERISTICS OF THE CONEJOS AQUIFER, THE MAJOR BEDROCK AQUIFER IN THE SAN JUAN SAG, EASTERN SAN JUAN MOUNTAINS, RIO GRANDE COUNTY, COLORADO – PART 2: IMPLICATIONS FOR GROUND WATER PROTECTION AND ENERGY DEVELOPMENT
The majority of the estimated 500+ water wells that draw water from the Conejos Formation aquifer in the mountainous part of Rio Grande County are for domestic or livestock use. This talk focuses on analysis of hydrogeologic characteristics and water quality from water well records, DST’s, and petrophysical analysis of logs of petroleum test wells.
This study revealed substantial heterogeneity and anisotropy in the Conejos aquifer. Available data provide evidence of deep circulation of ground water to several thousand feet depth within the Conejos aquifer and possibly in older underlying formations. Oil and gas naturally occur at shallow depths locally within the aquifer. This study found no formations of low hydraulic conductivity that hydrologically separate the underlying reservoir and source rocks from the shallower fresh-water aquifer.
The study recommendations to Rio Grande County were intended to protect potable ground water, propose appropriate safeguards for energy development to go forward, inform and involve the community, and guide further hydrogeologic studies. The study and recommendations provide an example of an approach to protect potable ground water and allow energy development to proceed in other communities where energy development is perceived as a threat to ground water resources.