A REPORT ON GROUNDWATER CONDITIONS IN THE BONGAIGAON AND BISWANATH DISTRICTS OF ASSAM Chandrayan Gupta HABITAT FOR HUMANITY FRONT 1 | P a g e Table of Contents Topic Page No. Introduction 1 Sources and Condition of Groundwater 1 Types of Water Assessment Units 6 Sources of Groundwater Recharge 6 Annual Extractable Groundwater Resources 8 Validity of Stage of Groundwater Resources 9 Yearly Municipal Budget and Their 9 Development Legal Provisions 11 Assessment of Groundwater Resource 14 Statistics Major Issues 15 Proposed Changes 17 Conclusion 18 1. Introduction In this paper, we shall be looking at the groundwater resources in two districts of Assam, namely Bongaigaon and Biswanath. The former has as per the 2011 census report a population of 7388041. While the 2021 census has yet to be carried out, estimates place the district’s current population at 8110192. On the other hand, the 2011 census found Biswanath’s population to be 6124913. No reliable estimates could be found as regards its current population. It is important to note at this juncture that data on Biswanath is regrettably scarce. It was formed relatively recently, in 2015. Prior to that, it was part of the Sonitpur district. Both are part of the State of Assam and are located along the floodplains of the Brahmaputra river, on its northern flank. While both districts share close proximity with Bhutan, Bongaigaon is nearer. It is only a little way to the country’s south. Biswanath has within its administrative borders 832 villages and 2 cities. One of the latter, Biswanath- Chariali, acts as the district’s headquarters. Bongaigaon has 563 villages and 5 cities within its control. The city of the same name, Bongaigaon, serves as its district headquarters. 2. Sources and Condition of Groundwater As mentioned, both Bongaigaon and Biswanath are located along the northern floodplains of the Brahmaputra river. That is where they derive most of their groundwater resources. Aside from that, rainfall is also a potent source in that regard. Bongaigaon is a high- rainfall area, having received over 600 millimeters of rainfall in the months of May, June, July, 1 District Census Handbook – Assam, Office of the Registrar General & Census Commissioner, India (Jun 17, 2021, 1:53 PM). https://www.censusindia.gov.in/2011census/dchb/1820_PART_B_DCHB_BONGAIGAON.pdf 2 Bongaigaon District Population (2020/2021), India Growing (Jun 17, 2021, 1:55 PM), https://www.indiagrowing.com/Assam/Bongaigaon_District. 3 Population (As per 2011 Census), Government of Assam, Biswanath District (Jun 17, 2021, 2:11 PM), https://biswanath.gov.in/portlet-sub-innerpage/population-as-per-2011-census. 1 | P a g e and September in 2020.4 Overall, it had an average rainfall of 265.21 millimeters. Biswanath, however, receives a much more modest monthly average of 90.83 millimeters.5 Neither district has any real shortage of groundwater. However, judging from historical trends (2013 onward), the water level is generally and gradually declining. It is not dramatic or alarming, but it is noticeable. For instance, Baitamari in Bongaigaon had a water level of 3.94 MBGL (meters below ground level) in March 20136. That number, which has consistently fluctuated, had in January 2020 settled at 4.41 MBGL7. While not enough to turn heads, such decline could be dangerous if allowed to continue. It is a similar story with North Salmara, also in Bongaigaon. It had in March 2013 a water level of 4.56 MBGL. In January 2020, that figure became 5.38 MBGL. The fall is greater in Biswanath, specifically in Biswanath-Chariali. While in March 2013 it had a water level of 2.55 MBGL, that had by January 2020 diminished to 8.39 MBGL. That is almost 6 meters of groundwater. However, it cannot be said that groundwater is declining all across the two districts. Most places have a water level that rises and falls each month but remains within a range of acceptable deviation from the average. Some even show improvement. One example is Bihupukhuri in Biswanath, which rose from 8.25 MBGL in March 2013 to 6.98 MBGL in January 2020. New Bongaigaon, which went from 4.41 MBGL to 2.67 MBGL, is another. Thus, holistically, Bongaigaon and Biswanath do not suffer from majorly worrying or disturbing water level depletion. However, there is enough of a decrease in enough parts of the districts to raise concern. A more prominent problem plaguing the two districts is water pollution. A study of the past 20 years of CGWB8 data9 brings out some troubling details. To understand them better, it is imperative to know that pH is a measure of how acidic or basic water is; EC is a measure of the electrical conductivity of water (which increases with the amount of organic and inorganic 4 Assam - Bongaigaon - Rainfall (mm.), Knoema (Jun 17, 2021, 3:24 PM), https://knoema.com/aulvzxc/district- wise-rainfall-data-for-india?tsId=1000760. 5 Climate Biswanath Chariali, Best Time To Visit (Jun 17, 2021, 3:51 PM), https://www.besttimetovisit.co.in/india/biswanath-chariali-1795804/. 6 Ground Water Year Book 2013-14, Central Ground Water Board (Jun 17, 2021, 4:50 PM), http://cgwb.gov.in/Regions/NER/Reports/GWYB%20NER%202013-14.pdf. 7 Ground Water Year Book 2019-20, Central Ground Water Board (Jun 17, 2021, 5:01 PM), http://cgwb.gov.in/Regions/NER/Reports/Final%20GWYBNER%202019-20%20for%20CHQ.pdf. 8 Ground Water Quality Data (2000-2009), Central Ground Water Board (Jun 17, 2021, 5:43 PM), http://cgwb.gov.in/WQ/GWQ_2000-2009.xlsx. 9 Ground Water Quality Data (2010 - 2018), Central Ground Water Board (Jun 17, 2021, 5:49 PM), http://cgwb.gov.in/WQ/GWQ_2010-2018.xlsx. 2 | P a g e salts); and TDS is a measure of how many particles of dissolved solids the water contains. The latter includes both inorganic salts such as calcium, magnesium, sulphates, and so on, and other inorganic compounds which are harmful to the human body. With that clear, we move on to the districts in question: Bongaigaon Determinant Part of District Not Falling Within Acceptable Range pH Bijni, Manikpur, Srijangram (Alkaline); Abhayapuri (Acidic) EC Manikpur, Chaprakata, Srijangram, Sidli, Phuloni, Chalantapara, Baitamari, Bijni, Gerukabari TDS Bijni, New Bongaigaon, Bongaigaon Biswanath Determinant Part of District Not Falling Within Acceptable Range TDS Biswanath Ghat As can be seen, Bongaigaon has quite a few areas where hydrological conditions are less than optimal. Of particular note is Bijni, where the water’s pH, EC, and TDS are too high. In contrast, Biswanath has only one area where only one quality determinant was detected as too high. Bongaigaon’s troubles do not end there. According to a study by UNICEF, water in 18 districts of Assam has an arsenic concentration above the permissible limit. Bongaigaon is one of them. 47 of its habitations have arsenic in their water.10 Another study assessed the health of Lake Tamrangabeel in Bongaigaon by examining its aquatic life. Although it concluded that 10 Ground water in 18 districts has arsenic, Assam Tribune (Jun 18, 2021, 12:41 PM), https://assamtribune.com/ground-water-in-18-districts-has-arsenic. 3 | P a g e the lake had good ecological potential, it also warned of “perturbation” regarding the lake’s condition, which was to be addressed before it was “too late”.11 A more worrying finding came when the drinking water quality of 15 schools in the Bongaigaon area of the Bongaigaon district was measured. Everything from the concentration of iron and turbidity (water clarity) to the presence of the bacteria E. coli was found to be higher than the permissible limit. The water was deemed acidic. None of the schools were concluded to offer safe drinking water, and the authors hoped school authorities would seriously consider taking action to improve water quality. Since schools obtain drinking water from underground, this was also a particularly grave assessment of the area’s groundwater quality.12 This discovery was supported by another study. This one was conducted in the Dhaligaon locality within the Bongaigaon area of Bongaigaon district. A few samples crossed the permissible limits of iron and turbidity. Over half of the samples had high concentrations of E. coli.13 Finally, there exists a study conducted in Bongaigaon, concerning the district’s municipal waste disposal. Among its conclusions, the most striking is that while Bongaigaon produces 25 tonnes of waste each day, only approximately 21 tonnes are disposed of safely. 4 tonnes each day makes 1460 tonnes a year. In addition to this waste creating an undesirable smell and turning its surroundings unhygienic, it also gets carried to rivers and other water bodies whenever there is rain. This severely harms the water quality.14 A district assessment study conducted to find out the feasibility of water supply projects contains a previously unpublished survey carried out jointly by UNICEF, the Public Health Engineering Department (PHED) and IIT-Guwahati. Out of the 1274 water sources it assessed 11 R.R Bhagawati, Susmita Gupta, Ecosystem Health of Lake Tamrangabeel, Bongaigaon District, Assam, India with Special Reference to Aquatic Insect Assemblage, Current World Environment (Jun 18, 2021, 12:54 PM), https://www.researchgate.net/publication/281561896_Ecosystem_Health_of_Lake_Tamrangabeel_Bongaigaon_ District_Assam_India_with_Special_Reference_to_Aquatic_Insect_Assemblage. 12 Ranu Roy, Munindra Nath Thakuria, Status of the Drinking Water Quality in Schools of Bongaigaon Area of Bongaigaon District of Assam, Nature Environment and Pollution Technology (Jun 18, 2021, 1:10 PM), https://neptjournal.com/upload-images/NL-31-23-(23)B-1019.pdf. 13 M.N. Thakuria, A.K. Talukdar, A Study on Physicochemical and Bacteriological Properties of Drinking Water in and around Dhaligaon Area of Chirang District of Assam, Asian Journal of Research in Chemistry (Jun 18, 2021, 1:46 PM), https://ajrconline.org/ShowPDF_Paper.aspx.