In article on the basis of field researches August, 2009. The problem of pollution by manganese of waters of the Bolshoy Irgiz river in the Saratov and Samara areas, and also on a water fence of Pugachev is considered. Results of chemical-analytical works about quality of river water in a channel, flood-plain lakes, ponds and water basins of Bolshoy Irgiza, and also on a city water fence and water supply systems are resulted.