The present study deals with water quality criteria, analysis of different physico- chemical and microbiological characteristics of rural and urban water sources specially drinking water in different areas adjacent to Rohtak, Haryana, India. The obtained values were compared with W.H.O and I.S.I standards for drinking water in order to assess whether the water samples are fit for human consumption or not. Attempts have been made to study the combined toxic effects of two important heavy metals namely Cadmium and Copper on fresh water teleost fish Channa Punctatus. The parameters selected for this study were bioassay experiments and certain physiological, biochemical and immunological changes.