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WATER MONITORING NETWORK

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Introduction:
The geographical characteristics and climate condition of the Assam region makes it very rich in water resources, both in term of surface water and sub-surface water. The surface water comprises rivers, lakes, ponds, beels etc. The lifeline as well as economy of the people of the state of Assam is closely linked with the water resources. Therefore, the monitoring of water quality of different water bodies and to maintain the wholesomeness is of prime importance. The Pollution Control Board, Assam is carrying out its mandatory responsibility of restoration and maintenance of the wholesomeness of aquatic resources in the State. The Board is monthly monitoring the water quality of most of the surface and sub-surface water bodies covering most of the districts of the State under National Water Quality Monitoring Programme (NWMP) of Central Pollution Control Board (CPCB).

Water Quality Monitoring Network under NWMP in Assam

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Pollution Control Board Assam is presently monitoring the water quality status of 237 numbers of monitoring location across the entire state of Assam which includes Rivers, Ponds, Beels, Ground Water under National Water Quality Monitoring Program (NWMP). Out of 237 monitoring locations, 170 nos. are from surface water source and remaining 67 nos. are from ground water source. Rivers, Ponds and Beels water quality is being monitored on monthly basis and Ground water quality on twice in a year basis as per CPCB protocol. (April & October)

Parameters Monitored

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The water samples are analysed for 8 core parameters and 16 other general parameters. The list of parameters observed in water quality monitoring in Assam under National Water Quality Monitoring Programme are given in Table No. 1.

Table No.1: List of Parameters Observed under
National Water Quality Monitoring Programme, Assam

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Water Quality of Rivers under NWMP
Water Quality of Brahmaputra River

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The Brahmaputra is one of the largest river systems of the world and the second largest river system in India. The Brahmaputra basin covers An area of 5,80,000 Sq. Km of which 1,94,413 Sq. Km. is in India. The mighty river Brahmaputra with a well-knit network of tributaries drains an area of about 56,480 Sq. Km in the State of Assam that accounts for about 72 per cent of the geographical area of the State. The River rolls down the plains of Assam from East to west for a distance of about 640 km before entering into Bangladesh.
To ascertain the water quality of Brahmaputra river, Pollution Control Board Assam has established 11 water quality monitoring stations under NWMP. The stations are at Bogibeel, Maijan, Nimatghat, Biswanathghat, Dhenukhana Pahar, Pandu, Chandrapur, Kacharighat (in Guwahati), Sualkuchi and Dhubri.
 

Water Quality of Tributaries of Brahmaputra River

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The mighty river Brahmaputra is characterised by a large number of tributaries, which confluence with it from both right bank and left bank.

Water Quality of Barak River and its Tributaries

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Barak is the second largest river system in Assam as well as in the North East India. The River with a total length of 9oo km covers an area of 52,000 Sq. Km. The river transverse a distance of 532 km in India up to the Indo-Bangla border. Barak is also a perennial river with large number of tributaries joint from both banks. The flows of the River in Assam decreases considerably during the winter months but they maintain their peak flow during Summer/rainy months.

Water Quality of Pond/Lakes/Beels

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Assam is well known for the presence of large numbers of Beels/lakes, Tanks and Ponds dotted all over the State. There are hundreds of water bodies under these categories, which occupy about 0.23 lakh hectares of area in the State. In this category, a total number of 66 ponds/Lakes/Beels has been considered under NWMP across the State for assessment of water quality.

Ground Water Quality

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The PCBA has been carrying out ground water monitoring in the State under NWMP. At present there are 67 numbers of ground water quality monitoring stations across the State. These stations are either well or tube well in nature. Ground water quality monitoring is carried out on half yearly basis i.e. one in the month of April and the other in the month of October.

 

Water Quality monitoring before, during and after immersion of Idols of Durga Puja

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Durga Puja is one of the biggest festival of Assam. The entire State wore a new look with festivals all around during the Puja. In this festival, devotees worship Goddess Durga through offering ‘Puja’ to beautifully crafted idols of Goddess Durga and few other Gods and Goddesses believed to be of her family, for five conjugative days. On the fifth day, after offering worship and competition of other rituals, the exquisitely crafted idols of Goddess Durga and others are immersed in water, mainly in rivers, beels, lakes and ponds, as a part of the celebration.
Keeping the circumstances in perspective and apprehending possible contamination of water bodies due to immersion of idols, the Pollution Control Board, Assam has been carrying out water quality monitoring at different immersion sites across the State as per the guidelines of CPCB. Moreover, the Board has also been issuing directives/guidelines regarding organizing Durga Puja in eco-friendly manner and crafting of idols using organic colours and naturally found substances.

Water Quality Monitoring before, during and after Ambubachi Mela

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The Ambubachi Mela is the most important religious fair celebrated in the Kamakhya Temple located on the top of Nilachal Hill of Guwahati, Assam. Ambubachi Mela is celebrated annually during monsoon season that happens to fall during the Assamese month Ahaar, around the middle of June. It is believed that the presiding Goddess of the Temple, Devi Kamakhya, the Mother Shakti, goes through her annual cycle of menstruation during this stretch. The Temple remains closed for three days during the mela. On the fourth day, the temple doors are re-opened to devotees, who are allowed to enter inside the temple to worship Maa Kamakhya once again. Every year, lakhs of pilgrims, starting from sadhus to devotees, from all over India and even from abroad comes to Guwahati to worship Maa Kamakhaya and to seek her blessings. It is important to note that gathering of lakhs of people in the temple site during the Ambubachi Mela and the use of water of the two ponds, Saubhagya Kunda and Kaso Pukhuri, located in the premises of the Temples as a part of ritual during the mela may have some impacts on their water quality. To assess such probable impacts, the Pollution Control Board, Assam has been carrying water monitoring of the said two pond before, during, and after the mela. However, due to Covid-19 pandemic, Ambubachi Mela was not organised in a festive manner for the years 2020 and 2021.

Critically Polluted Industrial Area

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Central Pollution Control Board, Delhi (CPCB) has identified Byrnihat industrial area of Assam in Kamrup Metro district as Critically Polluted Area (CPA) with Comprehensive Environmental Pollution Index (CEPI) Score of 78.31. In this regard, Hon’ble National Green Tribunal (NGT) vide its order in O.A. No. 1038/2018 dated 10-07-2019 also directed that adequate measures were needed to be taken in the form of time-bound Action Plan to restore and improve the environmental quality of the area. The directive further states that Environmental quality monitoring of CPA shall be carried out by concerned SPCB on half-yearly basis and data shall be placed in public domain.
As per the guidelines, the PCBA has prepared an Action Plan and submitted to CPCB. The Board also prepared a GIS-based Demarcation Map of the area with a core area of 2 Km radius and an impact area with 5 Km radius from the boundary of core area. The GIS database also includes information on industries, their locations. It is an effective tool to identify the source of pollution and initiate measures to promote and demonstrate proactive approach to environmental quality management in Byrnihat – Critically Polluted Area (CPA).
There are 55 nos. of industrial units within the Critically Polluted Area of Byrnihat. Out of these, 18 industries are located within the core area while 37 nos. are within the impact area.
PCBA has been conducting environmental monitoring within the CPA on half yearly basis and reports have been submitted to the CPCB and the same uploaded on the Board’s website.
For assessment of ambient air quality, the Board has set up a manual ambient air quality monitoring station at Byrnihat town and the station is in operation since March, 2021 and the reports have been submitted to CPCB through Environmental Air Quality Data Entry System.
The Board has set up a Continuous Ambient Air Quality Monitoring Station (CAAQMS) at Byrnihat town.

Polluted River Stretches

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The State of Assam is drained by a large number of rivers rich in aquatic resources. Most of the important towns of the State are located nearby the rivers. Rivers are the inseparable component of agrarian economy of Assam.  At present the PCBA is monitoring water quality at 206 monitoring stations across the State covering both Surface water and Sub-surface water under NWMP. Out of 206 monitoring stations 139 Stations are surface water and 67 stations are Sub-Surface. Based on the water quality monitoring data  of the parameter BOD (mg/l), for the year 2016 and 2017, Central Pollution Control Board (CPCB) has identified 44 polluted river stretches in Assam in the year 2018. The CPCB has classified the identified polluted river stretches into 5 priority classes based on the BOD values of the rivers. The priority classes are – Priority I (BOD value > 30mg/l), Priority II (BOD value 20- 30 mg/l, Priority III (BOD value 10-20) mg/l, Priority IV (BOD value 3-6 mg/l) and Priority V (BOD value 3-6 mg/l).
As per the directives of Hon’ble NGT, the PCBA has prepared Action Plan for all 44 polluted river stretches. The Action Plans have already been approved by CPCB and are at the implementation stage by concerned stakeholder departments.
The PCBA is continuously monitoring these 44 identified polluted river stretches as per the monitoring protocol provided by CPCB. The monitoring data for BOD value during the period from January 2021 to December 2021 shows that the water quality of 35 rivers out of 44 rivers have improved and at present as per the monitoring data of PCBA, there are only nine (9) rivers with BOD value higher than the prescribed standard. The results has been intimated by Board to CPCP and requested to re-notify the status of Polluted River Stretches of Assam based on recent monitoring data.

Status of polluted river stretches

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Priority	No. of stretches declared in 2018	No. of stretches in 2019 (Jan to December 2019)	No. of stretches in 2020 (Jan to December 2020)	No. of stretches in 2021 (Jan to December 2021)	No. of stretches in (Jan –December2022)	No. of stretches in Jan,2023-March,2023
Priority I	03	05	03	01	01	01
Priority II	01	-	01	03	03	03
Priority III	04	-	01	01	01	01
Priority IV	03	-	-	-	-	-
Priority V	33	09	01	04	04	04
Not Polluted	-	30	38	35	35	35
Total	44	44	44	44	44	44