Arsenic Poisoning in West Bengal : Treatment Plant



Replacement of Plant Columns and the Expense Involved

According to Pal-Trockener, if the tubewell water contains 1000 microgram/litre, then, after arsenic removal from about 4 lakh litres, the 2 columns must be replaced at an expense of about Rs.20,000/-.An estimate follows regarding the period of time after which the columns in the Domkal arsenic removal plants will need replacement.An average estimate obtained from villages shows that each of the plants is used by 300 people. Assuming that the water is used only for drinking, cooking, and other occasional purposes, each person will use 12 litres daily. Thus, each day the plant will free 300 x 12 = 3600 litres of water of arsenic. Let us also assume that on an average, the water in each plant contains 200 microgram/litre of arsenic before purification. So, after removal of arsenic from 20 lakh litres of contaminated water, the columns must be replaced. This condition will be reached in 18 months. Thus, after 18 months, each plant will require an expenditure of about Rs.20,000/- for column replacement.

Duties of the Administration

According to Pal-Trockener, the local administration decides where a plant is to be installed. After studying the 34 plants, it seems that detailed consideration was not given before installation of treatment plants location wise. If it is not so then why 5 plants were installed at 5 places where the tubewells have hardly any arsenic? 9 more plants are in places where the arsenic level is below the level set by the Govt. of India (Table-1). There is one plant each at Domkal thana and hospital, yet the water in both places has hardly any arsenic.

We have examined the tubewell water in 13 Gram panchayats of Domkal. From the 63 samples examined from Garibpur Gram Panchayat, 54 tubewells are seen to have arsenic content which, according to Govt. of India standards, makes them safe. In only 8 tubewells the content is little above the highest tolerable level, being between 50 and 65 microgram/litre. In only one tubewell, the water has 109 microgram/litre arsenic. Yet, the Garibpur Gram Panchayat has had six plants installed. While we were working in the area, 4 of these 6 treatment plants were not functioning. In the remaining 2, arsenic content was 33 microgram/litre and 48 microgram/litre respectively. It seems that the plants were installed without ascertaining the arsenic level in the water of Garibpur tube-wells. Again, in front of the Gramin Bank at Katakopra bazar under Raipur Gram Panchayat there is a plant although the area has piped water supply and the arsenic in the piped water is at a safe level. Yet, at Bagdanga-bagalpara under Juranpur Gram Panchayat, where there are innumerable arsenic-affected patients, as there are in Kushaberia village of the same Panchayat, no plant has been installed till May 2001.

Problems of the Pal-Trockener Plants and Solutions

1. The Pal Trockner plants are attached to existing tubewells. The attachment involves some changes in the tubewells, such as fixing a valve at their mouth. When the valve is in close position safe water is obtained and when in open position arsenic contaminated water is obtained which villagers can use for purposes other than drinking and cooking. These valves often get jammed, villagers cannot open them, and so they use arsenic contamination free water for all house- hold purposes.
2. The packing at the head of the tubewells to facilitate flow of water to the plant from the tubewell is often inadequate. Water erupts on pumping from the head of the tubewell as a result. The pressure is so great that the tubewell-handle springs up. This is how Safura Bibi and Amina Bibi injured their foreheads. Excessive use also damages the washer of the tubewells frequently.
3. The iron-removal column in the plant needs to be backwashed periodically. If not, yellow liquid emerges from the taps which the villagers do not wish to use. The mechanics appointed for backwashing are irregular in their visits according to the villagers. Although there is a chamber for collecting substances after backwashing, we never saw the chamber used in any plant.
4. Table-2, detailing the plants iron-removal efforts, shows that this part of the plant functions at best imperfectly, though this does not affect arsenic removal. It seems Pal-Trockener did not test their plants over a sufficient period of time in water having high iron-content.
5. Water obtained from the plants after arsenic removal has been seen to contain iron and some manganese. There is no indication as to how this affects the quality of the water.
6. Without testing the water, there is no way of ascertaining when the plant has become unable to remove arsenic.
7. From a technological angle, the Pal-Trockener plant is quite suitable for arsenic removal (not for iron). If the associated problems are solved, the plant can be used for arsenic removal in affected villages if budget permits. This applies also to plants manufactured by others for use in West Bengal. It appears to me associated problems are major, compared to technological problem.

How to make the plants fully functional

1. There is no problem with the arsenic treatment plants at Domkal thana, the BDO's office and the hospital. Maintenance personnel are regular in attending to their duty in these places. But, villagers say, personnel are reluctant to attend to the village plants, particularly in far-flung areas, and especially during hot summer and in the rainy season. Personnel must be subjected to strict rules, including punishment for negligence.
2. Since independence, villagers have believed that the Government will look after water supply, and that villagers themselves have no responsibilities in this matter. Even cattle drink water from a Rs.52,000/- plant. Waste could have been prevented, treatment plants could run smoothly by charging villagers only 20 paise per 10 litre of water. The resultant monthly income of Rs.2160/- from each plant could have gone towards maintaining the plant. Perhaps entrusting maintenance to some local club or the Panchayat, training workers, and paying them would ensure better running of the plants.
3. After 14 years of work in West Bengal Villages, and 7 years in Bangladesh villages, it is clear to me that any project can run only by involving villagers. Having discussions with them, inviting their opinion, giving them responsibility, building committees from among them, and, above all, involving their womenfolk will ensure the success of any project.

Publications on Arsenic Removal Plant

(1) Million dollar arsenic removal plants in West Bengal, India: Useful or not? M. Amir Hossain, Amitava Mukherjee, Mrinal Kumar Sengupta, Sad Ahamed, Bhaskar Das, Bishwajit Nayak, Arup Pal, Mohammad Mahmudur Rahman  and Dipankar Chakraborti. Water Quality Research Journal of Canada. 41(2), 2006; 216 – 225.

(2) Ineffectiveness and Poor Reliability of Arsenic Removal Plants in West Bengal, India. M. Amir Hossain,  Mrinal Kumar Sengupta, Sad Ahamed, Mohammad Mahmudur Rahman, Debapriya Mondal, Dilip Lodh,  Bhaskar Das, Bishwajit Nayak, Bimal K. Roy, Amitava Mukherjee, and Dipankar Chakraborti. Environmental Science & Technology, 2005, 39,4300-4306.  [Highlighted in News Section of Nature Magazine: “Arsenic - free water still a Pipedream. NATURE, Vol. 436, page 313, 21st July 2005.

Reports on Arsenic Removal Plant

(1) Performance of arsenic removal plant for treating groundwater with community participation, SOES, JU, June 2000.

(2) Fate of three crore-rupee arsenic removal plants in Murshidabad, West Bengal-India. School of Environmental Studies, Jadavpur University, Calcutta - 700 032, India, September 2001.

(3) A Study Report on Efficiency of 259 Arsenic Treatment Plants Installed in Ten Blocks of the Districts, North 24-Parganas, West Bengal. School of Environmental Studies, Jadavpur University, Calcutta - 700 032, India, January 2003.

(4) Follow-up study of Arsenic Treatment Plants in Murshidabad. School of Environmental Studies, Jadavpur University, March, 2003.

(5) Usefulness Of Arsenic Removal Plants: A Case Study In Kolsur Gram-Panchayet Of Deganga Block In North 24-Parganas, West Bengal, India. Fifth Report. School of Environmental Studies, Jadavpur University, December 2003.

(6) 6th report on Arsenic Removal Plants (ARPs) installed in arsenic affected villages of West Bengal.  Part-A: Physical aspects of the Arsenic Removal Plants (ARPs) installed in 4 different blocks of North 24-Parganas, West Bengal (March-April 2004).Part-B: Follow-up study (during May 2004) of the 20 ARPs with both physical and chemical aspects, which were found functioning well during March-April 2004 (Part A). School of Environmental Studies, Jadavpur University, Kolkata-700032, India, July 2004.