Strontium measured in wells tapping U.S. principal aquifers

Concentrations of strontium in samples of groundwater from drinking-water wells and shallow monitoring wells. Concentrations in drinking-water wells that exceeded the health-based screening level of 4,000 micrograms per liter largely occurred in carbonate-rock aquifers, particularly in southern Florida and central Texas, and in areas where upwelling brines mix with potable groundwater, for example in the Texas Panhandle.