In the San Luis Valley, the ongoing megadrought and a record-low snowpack are draining groundwater and increasing its concentrations of toxic metals. There are few protections for residents drinking from private wells.By Emily PayneJulie Zahringer hears a common refrain at her environmental laboratory in Alamosa, Colorado: A customer has been drinking well water on family land where they’ve lived for years, but recently noticed it has changed. They want to know why.