Radiological Quality of Water in Areas with Old Uranium Mines in the District of Viseu, Portugal

Radionuclides were determined in streams and rivers receiving mine drainage in areas of old uranium mines at the centre of Portugal. Results showed enhanced radioactivity levels in some areas impacted by uranium mining and milling wastes, but lower than several years ago. Current treatment of mine drainage contributed to decrease radioactivity levels in streams. In some horticulture areas, such as at Cunha Baixa, water from irrigation wells was contaminated by acid mine drainage and is not suitable for human consumption and for irrigation. Villages and towns near those old uranium mines currently have tap water from public networks supplied from artificial lakes in major rivers of the region. This tap water showed compliance with the recommended limits of total alpha and total beta radioactivity and is suitable for human consumption.