A study released earlier this month by the U.S. Geological Survey (USGS) found that water in the Rio Grande Aquifer System—which runs through Colorado, New Mexico, and West Texas—has high concentrations of some harmful minerals. The mineral found in the highest concentration is arsenic. According to Laura Bexfield, a hydrologist with the USGS, it’s pretty common for arsenic to be found in water that’s been exposed to sediment over a long period of time.
“Arsenic is naturally occurring in the rocks and sediment of the area,” she says. “It can be released under certain conditions that are favorable to that."
Other highly concentrated minerals found in the Aquifer include chloride concentrate, which can affect how water tastes, and total dissolved solids, a measure of the salinity in groundwater.
But Bexfield is quick to note that the water sampled in this study had yet to be treated. So the water quality is not an indication of what people are actually drinking. Still, these findings will help water suppliers understand what’s in the aquifers, so they can better treat and manage it in the future.
The study did not find any man-made elements that would make it unhealthy to drink.