The federal Safe Drinking Water Act, implemented in the early 1980s as mining began in earnest on Christensen Ranch, posed a potential hurdle to such ventures because it prohibited disposal of waste in aquifers. But the law allowed regulators to exempt aquifers if they determined that water was too dirty to use, or buried too deep to be worth pumping to the surface, or unlikely to be needed.
In 1982, when Wyoming officials anticipated the need for an aquifer exemption at Christensen Ranch, the state's then-governor, Ed Herschler, wrote to urge EPA officials to streamline their review of such requests and not to delay energy projects or interfere with Wyoming regulators. Steven Durham, the EPA's regional administrator at the time, wrote back to assure the governor the EPA would not second guess state officials, and that he had adjusted the rules so that they "should assure a speedy finalization of any exemptions."
Wyoming environment officials issued the first permit exempting several deep groundwater aquifers on the ranch from environmental protection in 1988. It said the water was of relatively poor quality, and was too deep and too remote to be used for drinking. The permit did not address the possibility that usable aquifers could lie in even deeper rock layers beneath the site.