investigation of microbial contamination of the mahabad dam reservoir in different seasons

Mahabad dam was constructed to supply drinking water, irrigation, and electricity generation on the mahabad river located west azerbaijan, mahabad. in this research, bacterial contamination of the water of mahabad dam was investigated. according to the geographical properties of the reservoir, 3 stations (near the dam crest, koter branch, and bitas branch) were selected and samples were taken via rottner from different depths of the reservoir during 12 months. bacterial contamination (total coliforms, fecal coliforms, and fecal streptococci) were studied after transferring the samples to laboratory. results indicated that values of total coliforms, fecal coliforms, and fecal streptococci were varied between 2.33 &± 1.20 and 1166.67 &± 33.33, 0.0 and 30.33 &± 6.74 and 0.0 &± 16.67 &± 6.33 mpn/100 ml respectively during over all the year. these values were in the allowed range according to the drinking water and recreation standards of iran.