Monitoring of Water Quality to Assess the Impact of Unscientific Sand Mining in the Catchment Areas of Umtyngar River, Meghalaya (North-Eastern India)

Author: Arnab Mandal, M.K. Choudhury and Prashant Gargava

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Abstract

Umtyngar River (Meghalaya, India) is the source of raw water for the supply of drinking water in Shillong City. However, Water quality of Umtyngar River is found turbid/ muddy due to impact of uncontrolled/ unscientific sand mining at the catchment area of the river. Citizens have occasionally reported the presence of an oily layer in the treated water from the Umtyngar River, supplied by Greater Shillong Water Supply, which is attributed to the excessive use of Alum to remove high levels of suspended solids in the river water. Thus, a scientific study was undertaken to investigate impacts on the water quality on the Umtyngar River caused by unscientific sand mining and to develop a sustainable management plan for restoration of river quality. Water samples were taken at upstream and downstream stations of Umtyngar River on a monthly basis starting from April, 2021 to November, 2022. Collected water samples have been analyzed for various physico- chemical parameters like pH, DO, BOD, COD, Conductivity, Turbidity, TSS& TDS. The sharp increase in values for the parameters conductivity, turbidity, and TSS in downstream station compared to upstream stations suggests that the majority of sand mining activities are located along the downstream station Umtyngar. Cluster Analysis & Principal Component Analysis also confirms that the downstream station Umtyngar is more affected by the unscientific sand mining at the river catchment area during the summer, monsoon, and post monsoon seasons of the year. Existing Sand mining practices were also deeply evaluated through extensive field visits. Particle size distribution of soil at the catchment areas was also examined to promote scientific sand mining practices and dry separation technology (like rotary sieving drum) to improve water quality in the river as well as considering economic angle of local communities.

Keywords

Cluster Analysis, Particle Size Distribution, Sustainable Management, Turbidity, TSS, Unscientific Sand Mining, Water Quality

Conclusion

The land, water, biotic, social and human environments have all suffered irreparable harm as a result of large-scale sand and gravel extraction from river banks. This is especially true of the rivers in Meghalaya in Northeast India, which are small and have few resources for riverbeds. In the present study undertaken, Physicochemical characteristic analysis of Umtyngar river water at different upstream & downstream stations throughout different seasons of the year and subsequent statistical analysis indicated that unscientific Mining of sands and gravels at the surrounding (East Jaintia) hills on the river bank of Umtyngar river is posing a great threat in water quality majorly in downstream station i.e., Umtyngar. The river water quality at downstream station Umtyngar is worst during the time of summer and monsoon. Apart from illegal mining, road construction activities in surrounding downstream stations (station-3) during the summer and monsoon of the year 2022 have also contributed in the deterioration of the water quality in terms of turbidity and TSS. It can be said that there is a pressing need to learn more about the intricate problems caused by sand mining activities on the way of life of nearby local communities. All stakeholders in the sand mining industries must work together to develop strategies for implementing sustainable mining practices. The information gathered during this inquiry, along with its analysis and interpretation, will help people better understand the condition of the water and the effects of unreliable sand mining on the Umtyngar River's catchment areas. More of these core investigations will be needed in the future, along with appropriate scientific monitoring techniques, in the Umtyngar Catchment area to keep the physico- chemical parameters under control for the benefit of the river's biotic components as well as for the greater good of humanity.

References

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How to cite this article

Arnab Mandal, M.K. Choudhury and Prashant Gargava (2023). Monitoring of Water Quality to Assess the Impact of Unscientific Sand Mining in the Catchment Areas of Umtyngar River, Meghalaya (North-Eastern India). Biological Forum – An International Journal, 15(5): 187-196.