8.1 Solutions for water problem in mines

In mining sector, which is prospective, very large, and capital intensive too, scientific approach toward groundwater management should be applied to curb and restrict groundwater overexploitation and maintain basic groundwater equation, that is, more recharge, less draft. To tackle water problem in both mine types, the following solutions are noteworthy:

• Best management practice (BMP): Number of solutions for open-pit as well as underground mines can be solved through case study experiences available internationally. Some best management practice (BMP) for water in mining and mine environment area are important from this view point [40, 41]. Guidance manual and case study experiences in various parts of the industry worldwide, provide solutions together with lessons (to be learnt) for better understanding.

Sometimes BMP is also referred as "best practice mining" or "best mining practice." In brief, BMP does not refer to any designed/formulated method but implies to "the continuousimprovement of mining and management practicesto maintain maximum performance for achieving an acceptable level of environmental protection." In doing so, it is necessary to incorporate and integrate economic, environmental, and social considerations into the mining operations in a practical way.

Mining involves mostly excavation, loading, and transportation operations. The most environment-unfriendly among these is the "transportation" and "dust generation by transportation." By adopting BMP the stress on environment is reduced because BMP emphasizes curtailing unscientific practices and avoiding shortcuts. Effective surface water utilization is the best management practice (BMP) for optimum use of rain-fed water resources. Similarly, pollution control measure

as applicable to large-sized public sector mines, that is, preventive approach, control at source, and zero liquid discharge (ZLD), is a solution through BMP.

• Integrated water resource management (IWRM): This becomes relevant when addressing water availability, water security, and water access for all users. IWRM involves the coordination of stakeholders in the water use of a site, an area or region to ensure economic and social development together with maintaining the ecosystem balance. Based on IWRM and stakeholders' experiences, water policy can be made sound, and balanced decisions in response to specific water challenges, being faced by the industrial company, can be taken. It is always desirable that cooperation between community, authorities, and organizations be maintained and public participation in water management be encouraged.

Thus, IWRM is an interdisciplinary approach to devise and implement efficient, equitable, and sustainable solutions to water and development problems. This approach is open and flexible and brings together decision-makers across the various sectors that impact water resources. IWRM principle ensures that water is sufficient for industrial operation and all users too. These days companies are concerned about continued water access in light of increasing scarcity. Their response is to maximize their efficiencies and limit their inputs. IWRM also involves "standardized water reporting," which is a low priority issue for the operating mines or industry. The issue with water reporting is that of hiding impacts of mine water-related issues with communities and regulatory authorities. Money/financial obligations are the principle cause for this hiding. Beyond this there exists a need to comply national environmental laws/ regulations, which should be complied and put into practice. Some of the barriers to IWRM in the past were the lack of hydrological data and models which have been overcome these days by the scientific studies. IWRM together with BMP (best mining and management practices) is capable to yield desired water resource management results as expected.


### Mining of Minerals and Groundwater in India DOI: http://dx.doi.org/10.5772/intechopen.85309

To curb the overexploitation (excessive withdrawal of groundwater from aquifer) for industrial purpose, imposition of tax or cess and pricing of the groundwater use is a way out. To conserve groundwater and rationalize the groundwater use by the mines, limited withdrawal permission is helpful in the excessive groundwater exploitation.

Rainwater harvesting (RWH), the most popular method of groundwater recharge, is the best solution to reduce dependence on groundwater. Implementation of these techniques and optimization of innovative alternates of RWH need to be encouraged according to the mine needs and requirements to provide solution locally.

• U/G versus surface mine: Underground (U/G) mines and surface mine's water-related problems are different. Therefore, solution to tackle water problem in underground mines are also typically different. Some encountered conditions of underground mines are:

Condition (i): sudden inrush of water or heavy water seepage from surface water body to underground mine workings in proximity, leading to inundation

Condition (ii): underground mining near "perched water table" (an accumulated/stored water underground)

Condition (iii): unprecedented or accidental connection of underground mine workings with aquifer containing infinite amount of water or water under pressurized conditions

Underground mines either operative or abandoned when filled with water pose a problem of "mine inundation." Many times such inundated waterlogged areas lead to mine disasters and also hamper normal mineral production in underground mines. The worst ever disaster caused by mine inundation in India was at "Chasnala Colliery" in the state of Bihar, India, in the year 1975 wherein 372 persons were drowned underground. Underground galleries approached the waterlogged old workings of an abandoned mine and faulty prediction of mine development had caused this accident to happen. The safest procedure to deal with inundation in mines is never to take the position of old working "for granted" until they have actually been proved by proper survey. No mine working which has approached within a distance of 60 m of any disused or abandoned working, whether in the same mine or in an adjoining mine, shall be extended further to endanger safety.

In underground mining, the mining operation near water bodies [44] assumes significant importance from research point of view. This is principally due to the uncertainty involved. Behavior of the surface water bodies (water head), intervening strata over the mine workings, its location (in the buffer zone/core zone of the mine lease area), and in between distances, plays considerable role and hence assumes significant importance. Therefore, geological, mining, and hydrological parameters must be looked while evaluating the real field situation, for example, topographical features such as hills/valley(ies) or ravines land, etc. should be considered. For solutions one must observe, examine, and check the proximity of old underground mine workings, whether the area is dry/damp or seeping in (heavy/ low). It is possible that the workings of adjacent mine may not be filled with water but the barrier pillar and its thickness are important and must be maintained as per the statutory requirement or the existing guidelines framed for the purpose.

To search solutions for water problem of underground mines, due consideration should be given for water impoundments (stagnant water bodies) on surface as well. Seasonal or perennial streams, standing water bodies, and sea vicinity to the

mine are important for pressure head created by the surface water or impoundments. Similarly, underground mining should not come closer to active oil and gas well (150 ft. minimum).
