The water quality data on rivers, lakes, ponds, tanks and groundwater locations being monitored under the network is evaluated against the water quality criteria and the monitoring locations in exceedence with respect to one or more parameters are identified as polluted, which requires action for restoration of water quality. The locations on rivers, lakes, ponds, tanks and groundwater not meeting the criteria are summarized ahead.

• The Biochemical Oxygen demand (BOD), one of the most important indicators of pollution, was observed in Amlakhadi at Ankleshwar (714 mg/L) followed by Ghaggar at Moonak, Punjab (626 mg/l), Khari at Lali village, Ahmedabad (320 mg/L); Musi at Hyderabad (225 mg/L); Sabarmati at Ahmedabad (207 mg/L); Kalinadi at Kannuaj, UP (136 mg/L); Khan at Kabitkhedi, Indore, MP (120 mg/L); Damanganga d/s Daman at Kachigaon (112 mg/L); Kalinadi at D/s of Muzzafarnagar, U.P (110 mg/l), Saroonagar, Ranga Reddy Dist. A.P (71 mg/l), Gandigudem at Medak Dist. (60 mg/l), Hindon at Saharanpur (60 mg/L); Yamuna at Sonepat (59 mg/l), Krishna D/s of Islampur (40mg/l), Satluj D/s Hussainwala Firozpur, Punjab (40 mg/L); Bhima at Pune (36 mg/L); Elangabeel System point, Assam (64 mg/l), Bharalu at Guwahati, Assam (43 mg/L); Sukhna at Parwanoo Dist., Solan (36 mg/l), Chandola Lake at Ahemdabad (36 mg/l), Hussain Sagar Lake, Budamaru, A.P (33 mg/l), Dhadar at Kothada (32 mg/L), Bhaleshwar Khadi at N.H. No. 8 (27 mg/l), Gomti at Sitapur U/s (25 mg/l), Chambal at Dholpur (25 mg/l), Yamuna between Delhi and Etawah (10-59 mg/L) and Tapi at Uphad, Mahashtra (25 mg/L). Due to high BOD dissolved oxygen in these stretches was observed most of the time either nil or very low.
• Total numbers of observations having BOD less than 3 mg/l, 3 to 6 mg/l and above 6 mg/l were 64%, 18% and 18%, respectively. The total number of observations having Total Coliform number less than 500 MPN/100 ml was 45%, between 500-5000 MPN/100 ml was 31% and exceeding 5000 MPN/100 ml was 24% MPN/100 ml. Similarly the number of observations having Faecal Coliform bacterial count less than 500 MPN/100 ml was 53%, between 500-5000 MPN/100 ml was 26% and 21% observations were exceeding 5000 MPN/100 ml.
• Faecal Coliform another important indicator of pollution in India was found highest in Yamuna river in Agra, Nizamuddin, Mazawali and Okhla (MPN 5.2 x10 6 to 3.7x10 6 ) followed by Hindon after confluence with Krishni (1.1x10 6 to 4.6x10 5 ); Ganga at Dakshineshwar & Uluberia (1.1x10 6 to 2.8x10 5 ); Damodar at Haldia (1.4x10 6 ); Khari at Lali Village, Ahmedabad (7.5x10 5 ); Sabarmati at Ahmedabad (1.1x10 6 to 4.6x10 5 ); Bharalu at Gauhati, Assam (2.4x10 5 ); Ganga at Varanasi ((1.1x10 5 ); Satluj at Ludhiana (1.1x10 5 ); Tapi at Ukai (1.5x10 5 ); Kalinadi at Muzaffarnagar (3.1x10 5 ); Damanganga at Silvasa (1.2x10 6 ); and Brahamputra at Dhenukapahar & Pandu (2.4x10 5 );

The water quality monitoring results were analysed with respect to indicator of oxygen consuming substances (Bio-chemical demand) and indicator of pathogenic bacteria (total colliform and faecal colliform). The result of such analysis shows that there is gradual degradation in water quality. The number of observations having BOD and coliform density has increased during 1995 to 2006. The water quality status for the period 1995 to 2006 in terms of number of observations having values of parameters in different ranges are given in the figure 2 to figure 4.

The numbers of observed BOD values less than 3 mg/l were between 57-68% during year 1995 to 2006. The maximum value of 68% was observed during 2005. This shows that there is improvement in the water quality.

The number of observed BOD values ranges from 3-6 mg/l was between 17-28% during year 1995 to 2006, the maximum value of 28% was observed in the year 1998. It was observed that there was a gradual decrease in number of observations having BOD between 3-6 mg/l.

The numbers of observed BOD value> 6 mg/l were between 14 and 19% during year 1995-2006 and the maximum value of 19% was observed in the year 2001 and 2002. It was observed that there was a gradual decrease to 14% in 2005 and increase to 18% in 2006 in number of observations having BOD >6.

The numbers of observed TC values < 500 MPN/100 ml were between 44-63% during 1995-2006, the value gradually increases to 63% in year 1999 which decreases to 45% in 2006.

The numbers of observed TC values ranges from 500-5000 were between 28-37% during year 1995-2006 the maximum value of 37% was MPN/100 ml observed in 1997 and this % was gradually decreases to 33% in 2000 which further decreases to 31% in year 2006. It was also observed that there was a gradual decrease in no. of observations having TC < 500 MPN/100 ml.

The numbers of observed TC values > 5000 were between 9-24% during year 1995-2006. The maximum value of 24% was observed in the year 2006. Minimum value of 9% was observed during the year 1999.

The numbers of observed FC values <500 MPN/100 ml was between 48-67% during year 1995-2006. The maximum value of 67% was observed in the year 1998 that gradually decreases to 48% in 1999, which again steadily rose to 53% in 2006.

The numbers of observed FC values ranges from 500-5000 MPN/100 ml was between 22-35% during year 1995 to 2006. The maximum value of 35% was observed in the year 1999, which gradually decreases to 26% in the year 2006.

The numbers of observed FC values > 5000 MPN/100 ml was between 7-21% during year 1995-2006. The maximum value of 20% was observed in 2000, which gradually decreases to 12% in the year 2005 and further increases to 21% in 2006.

The Water Quality trend of BOD in river Ganga, Yamuna, Sabarmati, Mahi, Tapi, Narmada, Godavari, Krishna, Cauvery, Mahanadi, Brahmani, Baitarni, Subernarekha, Brahmaputra, Satluj, Beas, Amlakhedi and Kali (East) depicting the data from 2002 to 2006 is presented in figure 5 to 22.