Assam

In this study, groundwater quality monitoring and evaluation of Greater Guwahati is presented based on the physico-chemical characteristics of thirty samples collected on grid pattern. The various parameters analyzed include pH, electrical conductivity, temperature, Dissolved Oxygen (DO), Total Dissolved Solids (TDS), alkalinity, hardness, Na⁺, K⁺, CA⁺⁺, Mg⁺⁺, NO₃^-, SO4^--, Cl^- and F^-. The results were compared with water quality standards prescribed by BIS and WHO.

The study attempts to do field and laboratory determination of soil classification properties in the Dudhnai river basin of Assam and Meghalaya. Point infiltration tests using double ring infiltrometer were conducted at various locations (forty-four sites) in respect of different land use conditions. Soil samples were collected from these infiltration testing sites.

The saturated hydraulic conductivity was determined in the field using Guelph Permeameter for the selected sites. The undisturbed soil samples and disturbed soil samples (50 cm below the ground) were collected and subjected to elaborate laboratory tests. 

The study presents a preliminary hydrological investigation of the Deepar Beel, a natural freshwater lake near Guwahati, and notes the theoretical aspects of the techniques to be used, methodologies and instruments for conducting a detailed study of the natural processes at hand.

Deepar Beel acts as a natural stormwater reservoir during monsoon period and is greatly influenced by the rapid urbanization and improper land use pattern of Guwahati. It receives a large portion of sewage of the city, but the preliminary investigations reveal that the Beel is largely free from significant levels of pollution. This is due to the dilution effects of large storm water runoff during monsoons as also the release of the Beel water to river Brahmaputra through the Khanajun outlet. Yet, the soil quality is found to have deteriorated to a large extent.

Various parameters of soil and water quality indicate that the process of eutrophication is in progress in this wetland. Although many trace elements are present in the Beel sediments, no known toxic effects are observed on aquatic life. Increasing sedimentation and reduction in lake water capacity and inflow are also observed.

The study applies the methodology developed by United States Department of Agriculture’s (USDA), Soil Conservation Services (SCS) for the nine subwatersheds of the representative Dudhnai basin in Assam & Meghalaya and estimates the runoff volume on a daily basis for the period 1986-1991. The method is widely adopted for the estimation of runoff from rainfall depths and takes into account the important physical aspects of a basin on which runoff depends such as land-use, hydrological soil cover and antecedent moisture condition.

The study on groundwater quality of Greater Guwahati analyses various trace elements in samples and ascertains that their concentration is much higher than the tolerance limit prescribed for drinking water. The trace element analysis focuses on metals such as Cu, Co, Cd, Fe, Zn and Pb.

Owing to the inadequacies of piped water supply, the Greater Guwahati area depends on groundwater from ringwells and tubewells for drinking purposes. Groundwater is mostly polluted from the effluents discharged by industries on land, seepage from sewage lines & tanks and application of pesticides on agricultural land. Due to the low flow velocity, groundwater once contaminated will remain so for longer periods. Metals assume significance because of their greater toxicity, accumulative and non-biodegradable behavior. 

The study aims to determine the climatological water balance of Krishnai river basin in Goalpura, Assam using the popular Thornthwaite’s concept of Potential Evapotranspiration (PET) to calculate the availability of water for various uses. The method offers a firm basis for appraising the problems related to water development projects in the planning stage and provides a sound footing for operating and managing the system. 

In the recent past, Dr. Dipul Choudhury from Guwahati (Assam), managed to ensure rainwater harvesting arrangements in his newly constructed multistoried building at Tarun Nagar, Guwahati (Assam).

Drinking Water Supply in rural areas of Assam ( India ) is managed by the Public Health Engineering Department (PHED), Government of Assam and the challenge is indeed enormous and achieving the targets requires well planned and strongly determined strategies and approach. Government has already formulated the necessary strategy to ensure sustained supply of safe drinking water in rural areas. However for achieving the desired end results from the Government initiatives, the community needs to be mobilized to own and sustain these programmes and to become an active partner in their implementation. For such a participatory demand driven approach, necessary awareness generation amongst the Community to realize the need for “total water security” and its impact on reduction of water borne diseases, is highly warranted.

The status of access to safe water in rural areas of Assam can be viewed at the Assam Public Health Engineering Department website.

The website of the Public Health Engineering Department of Assam, the nodal agency for the rural water supply programmes of the state is available below -

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