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 indicator of pollution, was observed highest in Amlakhadi river at Ankleshwar (947 mg/L) followed by Markanda river d/s Kala Aam, HP (855 mg/L), Khari river at Lali village, Ahmedabad (580 mg/L), River Sabarmati at Ahmedabad (380 mg/L), River Kalinadi at Gulauti, UP (165 mg/L), River Hindon at Binauli and Saharanpur (90-100 mg/L), River Satluj d/s Ludhiana (64 mg/L), River Khan at Kabitkhedi, Indore, MP (60 mg/L), River Musi at Hyderabad (42 mg/L), River Bhima at Pune (42 mg/L), River Damanganga d/s Daman (42 mg/L), River Bharalu at Guwahati, Assam (38 mg/L), River Yamuna between Delhi and Etawah (10-35 mg/L), River Kalana at Chandel, Goa (37 mg/L), River Tapi at Ajanad, Maharashtra (36 mg/L), River Dhadar at Kothala (30 mg/L). Because of high BOD, dissolved oxygen in these stretches was observed either nil or very low most of the time in these stretches.

• Total numbers of observations having BOD less than 3 mg/l, 3 to 6 mg/l and above 6 mg/l were 68%, 18% and 14%, respectively. The total number of observations having Total Coliform number less than 500 MPN/100 ml was 46%, between 500-5000 MPN/100 ml was 31% and exceeding 5000 MPN/100 ml was 23% MPN/100 ml. Similarly the number of observations having Faecal Coliform bacterial count less than 500 MPN/100 ml was 60%, between 500-5000 MPN/100 ml was 28% and 12% observations were exceeding 5000 MPN/100 ml.

• Fecal coliform, another important indicator of pollution, was found highest in Yamuna River in Delhi (MPN 3.9 x10⁷) followed by River Hindon after confluence with River Krishni (2.1x10⁶), River Ganga at Dakshineshwar (7x10⁵), Rabindrasarovar, Kolkata (8.5x10⁵), River Damodar at Haldia (4x10⁵), River Khari at Lali Village, Ahmedabad (2.8x10⁵), River Sabarmati at Ahmedabad (2.4x10⁵), River Bharalu, Assam (2.4x10⁵), River Ganga at Varanasi ((1.1x10⁵), River Satluj at Ludhiana (0.9x10⁵), River Tapi at Bhusaval (9x10⁴), River Kalinadi at Muzaffarnagar (9x10⁴), River Ghaggar (9x10⁴), River Sabarmati at Ahmedabad (7.5x10⁴), River Gomti at Lucknow (7x10⁴), River Godavari at Nasik (5x10⁴) and River Musi at Hyderabad (4x10⁴).

• Lakes and Tanks that have high concentration of organic matter and does not comply to the standard limits for BOD are Hussain Sagar lake, Dharamsagar tank, Bibinagar lake, Kistarareddypet tank, Saroornagar lake, Pulicate lake, Gandhigudem tank, Heballa Valley lake, Kayamkula lake, Kodungalloor lake, Osteri lake, Bahour lake, Udhagamandalam lake, Kodaikanal lake, Periyar lake, Vembanad lake, Ashthamudi lake and Paravur lake. Lakes and Tanks having very low DO and high BOD that does not meet the water quality criteria limits are Kankoria Lake, Chandola lake, Pichola Lake, Udaisagar lake, Fatehsagar lake, Kayalna lake, Nakki lake, Pushkar lake, Lower lake Bhopal, Renuka lake, Harike lake, Naini lake, Ramgarh lake, Rabindra Sarobar lake, Elangabeel System, Goy Sagar Tank, Loktak lake at Sendra, Umiam lake at Barapani, Ward Lake at Shillong, Thadlaskena lake and Laxminarayan Bari Place Lake.

• The groundwater monitoring locations, where high conductivity exceeding water quality criteria for irrigation were observed at Ramagundam, Bollaram Panchayat Office, Pashamaylam, Vishakhapatnam (near Rama Temple) and Kakinada (near Pratap Nagar Bridge) in Andhra Pradesh; Nerol in Gujarat; Alwaye in Kerala; Circuit house, old police Barracks, Ottavathilpalli, near Helipad, MPSAF Quarters and Government Press in Lakshadweep; along Chunamber river in Pondicherry; and Pali, Jodhpur and Vidhani Village (Jaipur) in Rajasthan. Groundwater locations with BOD levels higher than the criteria are at Vijayawada, NTPC ash pond- kundanpally, Bibi nagar Primary school, Rudravally, near Tungabhadra river in Kurnool and Nandyal in Andhra Pradesh; Karbianglong and Bongaigaon in Assam; Kala Amb, Barotiwala and Paonta Sahib in Himachal Pradesh; JB School, Kadatpalli, near SB School, Ottavathilpalli and Chakikilum in Lakshadweep; Collector Well in Thirupuvanam and along Chunamber river in Pondicherry; near Kansua Nallah in Kota, Pali town, Jodhpur in Rajasthan; IOC Refinery Haldia, Barasat municipality in north 24 Parganas in West Bengal. Total coliforms are exceeding the criteria limits in groundwater locations in Silcher, Barpeta, Bongaigaon, Sibsagar, Guwahati in Assam, Chekkillam, Government press and old Police Barrack in Lakshadweep. pH is observed in acidic range at Kundra in Kollam, Punkunnam in Trissur, Kalamassery in Ernakulam, Punalur and Kannur in Kerala; and Capital hospital in Bhubaneshwar Orissa.

WATER QUALITY TRENDS

The water quality monitoring results obtained during 2005 indicate that the organic and bacterial contamination continue to be critical in water bodies. This is mainly due to discharge of domestic wastewater mostly in untreated form from urban centres of the country. Secondly, the receiving water bodies also do not have adequate water for dilution. Therefore, the oxygen demand and bacterial pollution is increasing day by day.

The water quality monitoring results were analysed with respect to indicator of organic matter (Bio-chemical oxygen demand) and indicator of pathogenic bacteria (total coliform and faecal coliform). The trends of percent of observations in different ranges of pollution during last 11 years (1995-2005) with respect to BOD & Total coliform and Faecal Coliform are graphically shown in Figures illustrated below.

Biochemical Oxygen Demand (BOD)

The number of observed BOD values less than 3 mg/l were between 57-68% during year 1995 to 2005. The maximum value of 68% was observed during 2005. This shows that there is a gradual improvement in number of locations meeting the level of desired criteria.

The number of observed BOD values in 3-6 mg/l range were between 18-28% during year 1995 to 2005, 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 number of observed BOD value more than 6 mg/l were between 15 and 19% during year 1995-2005 and the maximum value of 19% were observed in the year 2001 and 2002. It was observed that there was a gradual decrease in number of observations having BOD >6 mg/l.

Fig. : River water quality ternds in terms of percent no. of observation in various BOD ranges

Total Coliform (TC)

The number of observed TC values less than 500 MPN/100 ml were between 44-63% during 1995-2005, the values gradually increases to 63% in year 1999 and then decreased to 46% in 2005. It was observed that first the values gradually increased and then decreased in number of observations having TC < 500 MPN/100 ml.

The number of observed TC values in 500-5000 MPN/100 ml range were between 28-37% during year 1995-2005.The maximum value of 37% was observed in 1997 and this gradually decreased to 31% in 2005. It was observed that there was a gradual decrease in number of observations having TC between 500-5000 MPN/100 ml.

The number of observed TC values more than 5000 MPN/100 ml were between 9-23% during year 1995-2005. The maximum value of 23% was observed in the year 2005.

Fig. : River water quality ternds in terms of percent no. of observation in various TC ranges

Faecal Coliform (FC)

The number of observed FC values less than 500 MPN/100 ml were between 48-67% during year 1995-2005. The maximum value of 67% was observed in the year 1998 that gradually decreased to 48% in 1999, and rose to 60% in 2005. The number of observed FC values ranges from 500- 5000 MPN/100 ml was between 22-35% during year 1995 to 2005. The maximum value of 35% was observed in the year 1999, which decreases to 28% in the year 2005. The number of observed FC values ranges > 5000 MPN/100 ml were between 7-20% during year 1995 -2005. The maximum value of 20% was observed in 2000, which gradually decreases to 12% in the year 2005.

Fig. : River water quality ternds in terms of percent no. of observation in various FC ranges

Based on observations recorded during 2004 following main conclusions are drawn :-

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 and require action for restoration of water quality. The locations on rivers, lakes, ponds, tanks and groundwater not meeting the criteria are summarized briefly as follows :-

· During 2004 the highest BOD, one of the most important indicators of pollution, was observed in Amlakhadi at Ankleshwar (947 mg/L) followed by Markanda d/s Kala Amb, HP (855 mg/L); Khari at Lali village, Ahmedabad (580 mg/L); Sabarmati at Ahmedabad (380 mg/L); Khan at Kabitkhedi, Indore, MP (150 mg/L); Kalinadi at Gulauti, UP (165 mg/L); Hindon at Binauli and Saharanpur (90-100 mg/L); Satluj d/s Ludhiana (64 mg/L); Musi at Hyderabad (42 mg/L); Bhima at Pune (42 mg/L); Damanganga d/s Daman at Kachigaon (42 mg/L); Bharalu at Guwahati, Assam (38 mg/L); Yamuna between Delhi and Etawah (10-35 mg/L); Kalana at Chandel, Goa (37 mg/L); Tapi at Ajanad, Mahashtra (36 mg/L) and Dhadar at Kothada (30 mg/L). Due to high BOD dissolved oxygen in these stretches was observed most of the time either nil or very low.

· Similarly fecal coliform another important indicator of pollution in India was found highest in Yamuna river in Delhi (MPN 62 x106) followed by Hindon after confluence with Krishni (2.1x106); Ganga at Dakshineshwar (7x105); Rabindrasarovar, Kolkata (8.5x105); Damodar at Haldia (5.5x105); Khari at Lali Village, Ahmedabad (2.8x105); Sabarmati at Ahmedabad (2.4x105); Bharalu at Gauhati, Assam (2.4x105); Ganga at Varanasi ((1.4x105); Satluj at Ludhiana (0.9x105); Tapi at Bhusaval (9x104); Kalinadi at Muzaffarnagar (39x106); Ghaggar at Sardulgarh (9x104); Sabarmati at Ahmedabad (2.4x105); Gomti at Lucknow (7x104); Godavari at Panchvati (5x104) and Musi at Hyderabad (4x104).

· Total number of observations having BOD less than 3 mg/l, 3 to 6 mg/l and above 6 mg/l were, 66%, 19% and 15% respectively. The total number of observations having Total Coliform number less than 500 MPN/100 ml was 44%, between 500-5000 MPN/100 ml was 34% and exceeding 5000 MPN/100 ml was 22% MPN/100 ml. Similarly the number of observations having Faecal Coliform bacterial count less than 500 MPN/100 ml was 59%, between 500-5000 MPN/100 ml was 27% and exceeding 5000 MPN/100 ml was 14% MPN/100 ml.

· Water quality of river Beas at D/s of Pathankot and Mukerian and river Satluj at D/s of Budhanala in Ludhiana, at Boat Bridge Dharmkotnakodar Road and at D/s of East Bein in Jallandhar found deteriorated and degraded as compared to stipulated requirement.

· River Ganga at downstream of Narora, Kannauj, Varanasi, Kanpur, Bahrampur, Dakshineshwar, Uluberia and Palta is not meeting the desired water quality for bathing as well as organized water supply for drinking purpose. The water quality of river Yamuna is deteriorated after the intake point of Warzirabad Barrage and does not confirm to criteria for beneficial uses for over 500 km that extends beyond Etawah. Water supply of Agra is worst affected due to high BOD and Ammonia in the river Yamuna. Other tributaries having higher concentration of pollutants are Hindon near Binauli town and Ghaziabad; Kalinadi (tributary of river Hindon) at downstream of Muzzafarrnagar; river Kali (tributary of river Ganga) along Meerut, Modinagar, Hapur, Bulandshahr and Gulaothi. River Chambal at Nagda, Kota and Rameshwarghat (Sawaimadhopur); river Khan at Kabit Khedi near Indore, river Kshipra at Ramghat (Ujjain) and Triveni Sangam; Tons at Madhavgarh; Mandakini at Chitrakoot; Betwa before confluence to Yamuna at Hamirpur; and Sone at Koelwar in Bihar. River Damodar near Mujher mana village, after confluence of Tamla Nallah, at Haldia Downstream; Barakar at Asansol and the Rupnarayan at Geonkhali before confluence to River Ganga; Ramganga at Kannuj; and Gomti at Lucknow downstream are also not meeting the desired criteria.

· The mainstream of River Brahmaputra is relatively clean however its tributaries Full Nagarjan, Teesta, Digboi, Bharalu, Bhogdoi, Deepar Bill, Dickchu, Maney Khola and Ranichu are polluted.

· River Mahi is conforming to the desired water quality at all the monitoring locations.

· River Sabarmati is grossly polluted in the reach of Ahmedabad to Vautha. water quality of mainstream of Sabarmati and tributary streams Shedi and Khari is acidic in some reaches with very high COD, BOD, Total and Faecal Coliforms, Conductivity and very low DO. The acidity of river water is attributed to industrial wastewater discharges.

· The mainstream of River Narmada and tributary stream Chota Tawa are confirming to water quality for all the criteria parameters.

· The water quality of mainstream of river Tapi is exceeding criteria limits at Uphad village, Ajnad village, Bhusawal upstream and river Girna at Malegaon and Jalgaon.

· The water quality of mainstream of Mahanadi does not meet the criteria with respect to BOD at downstream of Paradeep, Cuttack and Sambhalpur due to discharge of untreated sewage from cities of Cuttack and Sambhalpur. The Water Quality of tributary stream Seonath, Hasdeo, Ib, Kathjodi and Birupa are complying to the water quality criteria. Other streams such as Kharoon, Kuakhai downstream of Bhubaneshwar and Kathajodi downstream of Cuttack are not meeting the criteria limit in respect of BOD and Total Coliform.

· The water quality of mainstream of Brahmani with respect to BOD,Total and Faecal Coliform is exceeding the criteria limit at downstream of Pamposh, Rourkela and Kamalanga due to wastewater discharges from the industrial and residential complexes of Rourkela,Talcher, Bhuban and Dharamashala. The water quality of tributary streams Sankh, Koel and Karo are meeting the criteria with respect to indicators of organic and bacterial pollution. The water quality of major tributary streams Baitarni is exceeding the criteria at Chandbali and Dhamra. The Total coliform does not meet the criteria at Anandpur, Jajpur, Chandbali and Dhamra.

· In river Subarnarekha, BOD is exceeding the criteria at Jamshedpur whereas the Total Coliform and Fecal Coliform number are quite high at Rajghat that indicate sewage discharges in the river.

· The water quality of river Godavari at downstream of Nasik and Nanded in Maharashtra and at Rajahmundry downstream in Andhra Pradesh does not meet the criteria due to proximity of large city. The Water Quality of tributaries streams Wainganga at ashti and at Balaghat; river Nira at Pulgaon Cotton Mills, Wardha; river Wardha at Rajura Bridge; river Maner at Somnapalli; river Panchavati at Ramkund and river Manjeera near Ganapathi Sugars, Medak District, Andhra Pradesh are not meeting the criteria for BOD.

· River Krishna does not meet the water quality criteria at Karad, Sangli and Hamsaladeevi, Devasagar Bridge in Karnataka, at downstream of Narayanpura Dam, at Tintini Bridge, at Thangadi, at Gadwal Bridge and at Wadapally. River Bhima at Pune downstream of Bundgarden, Bhima at Pune upstream, Bhima at Pargaon after confluence with Mula and Mutha, Bhima after confluence with river Daund at Takli; River Panchganga at Ichalkaranji; river Nira at Sarole Bridge; river Tunga D/s of Shimoga Town; Bhadra at Maleshwaram D/s of KIOCL, Bhadra at D/s of Bhadravati and river Musi at upstream and downstream of Hyderabad are potentially polluted locations having higher BOD levels.

· River Pennar is meeting the desired water quality criteria at all locations.

· The Water Quality of River Cauvery is not meeting the desired water quality criteria at Bhavani, Pallipalyam, Erode, Velore, Mohanur, Tiruchirapalli Downstream, Trichy, Pitchavaram, and Kushal Nagar. The water quality of tributary streams Hemavati, Shimsa, Arkavati, Lakshmantirtha, Kabbani, Bhavani and Amravati indicates that DO is not meeting the water quality criteria at Bhavani, at Sirumugai and at Bhavani Sagar; and river Arkavati at Kanakpura downstream with respect to BOD.

· River Damanganga at Kachigaon Downstream; Kolak at Vapi; Ambika at Billimora; Kolak at Pataliya; Amlakheri at Ankleshwar; Bhadar at Jatpur and Mindola are exceeding the criteria limit for BOD. The water of river Amlakhadi was found acidic as the minimum pH was observed as 2.2. River Zuari is relatively clean river and meeting the criteria parameters where as Mandovi around Panaji is not meeting the criteria limit. River Patalganga at Shilphata; river Ulhas upstream Badlapur; Patalganga near intake of MIDC waterwaorks; Bhatsa at D/s of Pise Dam and Kalu at Atale village are not meeting the criteria due to higher level of BOD in these rivers. The rivers in Kerala are meeting the criteria limit for BOD except in river Periyar at Kalady. The bacterial pollution is observed in almost all the rivers. BOD observed more than criteria limit in river Nagavali at Jaykaypur; Arasalar at Karaikal (Pondicherry); Tambiraparni at Tirunalveli and Palar at Vaniyambadi are found polluted due to higher levels of BOD. The river Ghagger is grossly polluted at majority of monitoring locations such as at Ratanhedi D/s of Patiala Nadi; at Moonak; at Chandarpur Siphon; upstream of Sardulgarh and at downstream of Sardulgarh due to the discharge of municipal and industrial wastewater. River Nambul at Hump Bridge, at Heirangoithong (Manipur); River Umtrew at Byrnihat East and River Kharkhala near Sutnga Khlieriat,Jayantia Hills are observed as polluted due to high level of BOD.

· Lakes and Tanks having high concentration of organic matter and does not comply to the standard limits for BOD are Hussain Sagar lake, Bibinagar lake, Kistarareddypet tank, Saroornagar lake, Pulicate lake, Gandhigudem tank, Heballa Valley lake, Kayamkula lake, Osteri lake, Bahour lake, Udhagamandalam lake and Kodaikanal lake. Lakes and Tanks having high BOD that does not meet the water quality criteria limits are Kankoria Lake, Chandola lake, Pushkar lake, Lower lake Bhopal, Renuka lake, Harike lake, Naini lake, Ramgarh lake, Rabindra Sarobar lake, Elangabeel System, Loktak lake at Sendra, Umiam lake at Barapani, Ward Lake at Shillong, Thadlaskena lake and Laxminarayan Bari Place Lake.

· The groundwater monitoring locations observed with high conductivity which exceeds water quality criteria for irrigation are observed at Ramagundam, Bollaram Panchayat Office, Pashamaylam, Vishakhapatnam (near Rama Temple) and Kakinada (near Pratap Nagar Bridge) in Andhra Pradesh; at Nerol in Gujarat; along Chunamber river in Pondicherry; at Santhla village, Bhiwadi and at Vidhani Village (Jaipur) in Rajasthan. Groundwater locations with BOD levels higher than the criteria are at NTPC ash-pond, Kundanpally; near Tungabhadra river in Kurnool and Nandyal in Andhra Pradesh; near Swarnamukhi river, Srikalahasti; at Paonta Sahib in Himachal Pradesh; Collector Well in Thirupuvanam; along Chunamber river in Pondicherry; at Pali town, Jodhpur in Rajasthan and at Rishra in West Bengal. Total coliforms are exceeding the criteria limits in groundwater locations in Barpeta, Bongaigaon and Guwahati in Assam. pH is observed in acidic range at Kundra in Kollam, at Kalamassery in Ernakulam, at Khandagiri area in Bhubaneshwar and at Capital hospital in Bhubaneshwar, Orissa.