author(s)
Mamta Rani, Pratima Akolkar, H. S. Bhamrah

abstract
Clean to slight pollution in biological water quality was observed in River Yamuna at Yamunotri and Hanuman chetti, in terms Biological Water Quality Criteria. River Yamuna was moderately polluted from Okhla Barrage to Allahabad throughout the year. At Etawah, the water quality became severely polluted during summer season. Water quality of River Yamuna at Yamunotri, meets the Primary Water Quality Criteria in terms of pH of 8.1, DO of 7.8 mg/l, BOD of <2 mg/l and Total Coliform count of <2 MPN/100 ml used for drinking water without conventional treatment but after disinfection Class A and Outdoor bathing Class B and Class ‘C’ and drinking water source after conventional treatment. Average Total Coliform counts of 24775 – 66357500 MPN/100 ml did not meet the criteria of Total Coliform counts of 5000 MPN/100ml for drinking water source with conventional treatment followed by disinfection(Class ‘C’) in River Yamuna at downstream Yamunotri. Free Ammonia levels of 1.4-6.6 mg/l were unsuitable for propagation of wildlife, fisheries under Class ‘D’ in River Yamuna from Okhla Barrage to Etawah. Entire stretch of RiverrnYamuna was found to meet the desired criteria for irrigation, industrial cooling and controlled waste disposal (Class ‘E’) in terms of conductivity levels of 83-1087 µmhos/cm.