Geochemistry of radionuclides in groundwaters at the former uranium and radium mining region of sabugal, portugal

Abstract

Recent concerns over potential radiological hazards posed by the uranium mining and milling wastes have led to assess the radioactivity in groundwaters of County of Sabugal, central region of Portugal. Waters from the Bica Mine were the highest concentrations measured in waters from this region. Water from irrigation wells generally showed low concentrations with the exception of several wells near the Bica Mine. Waters from public drinking water supplies in the villages and towns contained 238U, 226Ra, 230Th, 210Po and 232Th in concentrations below values recommended for drinking water. Only one local spring exceeded the limit for alpha radioactivity. Overall water resources were not significantly contaminated by the historic uranium mining activities. Nevertheless, mine waters from Bica Mine still require treatment to prevent dispersal of acid mine drainage and radionuclides into aquifers. Other mines nearby, with near neutral pH and anoxic waters show low dissolved concentrations of uranium.