About 5 billion of the 7.5 billion people on Earth live in places where drinking water is becoming harder to find. The remedy is often to drill a water well deeper, but a new study published by UCSB researchers concludes there may be less drinking water in the United States than has been assumed. The researchers looked at fresh water in wells and the briny water below in the major sedimentary basins of the U.S., including the San Joaquin.
Contaminants from the surface plus those from injected fluids, as well as the fact that deep, old water tends to be brackish, are complicating the picture. One reason this matters is that brackish water, which has more salt or solids in it from eons of contact with underground rock, is being desalinated by more and more water companies to create drinking water, through processes like reverse osmosis.
The study builds on research done on groundwater levels across the country, “data mining” an impressive database from the U.S. Geological Survey, but this time from the “bottom up” in aquifers. “Combining top-down and bottom-up studies can give us a window into where fresh, uncontaminated groundwater exists,” explained study co-author Debra Perrone, an assistant professor at UCSB’s Environmental Studies department, “and where this window is getting smaller, either because the ceiling is coming down or the floor is coming up.”