Prediction of Groundwater Withdrawal for a Composite Coal Mine Over a Mine Life: A Case Study

Abstract

There are three opencast Coal Mine pits in the area, namely Pandharkawda OC, Marki OC, and Mini Marki OC. The Opencast Pit at Marki has an area of 44 ha and will attain a maximum depth of 50 mbgl with open pit mine life of 10 years. Pandharkawda Opencast is having an area of 40 ha with maximum depth of 45 mbgl having opencast mine life of 9 years. Mini Marki OC is the third small Opencast Pit which will start production in 28th Year i.e., after the closure of Pandharkawda Underground. It has a small area of 7.25 ha with life span of 3 Year (28th to 30th Year). Thus, the total opencast mining area is 91.25 ha. In the area, two underground (UG) patches are proposed namely Marki and Pandharkawda UG which will commence production after completion of opencast workings. These sections will attain a maximum depth of 150 mbgl. Life span of Marki UG will be 20 Years (10th to 27th Year) and that of Pandharkawda UG will be 18 Years (9th to 27th Year). Coal Mine is producing coal @ 0.30MTPA peak since 2017. The Coal Mine was operated for 3 years from 2011 to 2013 and again resumed production since 2017. Hence, the opencast mine Pandharkawda OC, Marki OC will last its operation till first 9 years, and underground Coal Mine will continue from 9th year onwards till 27th year. Total planned mine life of Marki Mangli-I Coal Mine is around 20 years whereas Mini Marki OC will start its operation from 27th years onwards till 30th year. Study for prediction of groundwater withdrawal for subjected Coal Mine was carried out pre-monsoon and post-monsoon period in year 2016 to quantify the groundwater withdrawal from coal mining operations. The predicted quantity of groundwater withdrawal from Coal Mine is used by mine management to create groundwater recharge structure to compensate the groundwater discharge during mine operations.