Responsible Tailing Management HZL

RESPONSIBLE TAILING MANAGEMENT Tailings are a mixture of powdered rock and water that is left over after the economic minerals/metals are removed from the ore, and resultant of number of sizing, grinding and processing steps. From the mill, the tailings are often pumped to slurry into scientifically designed containment areas, a Tailings Storage Facility (TSF).

HZL recognizes the impacts of mine tailings and tailings facilities on the environment, nearby communities and other stakeholders. We are taking extensive measures for construction, operation, maintenance and closure of facilities that mitigate risks of tailing dam failure and incorporates best available technologies as guided by Vedanta’s Tailing Management Facility Standard. Wherever possible, we repurpose tailings materials and waste rock as backfill to stabilize our underground mining operations. Remaining tailings are then placed in a specially-designed tailings storage to minimize the environmental, social, and economic risks.

All the Company’s tailings facilities are designed and constructed to the highest engineering standards and meet regulatory requirements and best in class benchmarked practices.

VEDANTA’S TAILING MANAGEMENT FACILITY (TMF) STANDARD

Performance standards for TMFs are in place across the Vedanta Group, focusing on the full lifecycle of the tailings process, from investigation, planning and design, to construction, operations, closure and rehabilitation. It is applicable to all existing and future tailing facilities in mining operations.

Key Features of standard includes:

TMF PLANNING AND DESIGN

• Site selection must be based on a comprehensive environmental and social impact assessment, economics, and public health and safety risk over the life cycle of the tailing facility as per Good International Industry Practice.

• Dam break analysis must be conducted based on the advice of the designer/ consultant to quantify the TMF-related risks if the TMF is located upstream or close to communities or sensitive environmental areas.

• Design must be based on best available technology, to minimize the environmental, social, and economic risks, at an optimal total cost of ownership over the life cycle of the operation.

TMF CONSTRUCTION

• Every Vedanta unit will appoint a qualified third-party consultant for supervision and quality assurance of their TMF construction, and will obtain appropriate construction reports

TMF OPERATION AND MANAGEMENT – ALL VEDANTA UNITS MUST:

• have a tailings management committee with defined roles and responsibilities led by the process or ash department;

• develop, operate, monitor and manage the TMF in line with their Tailings Management Plan; • conduct periodic risk assessments of the TMF and develop mitigation plans to minimize public

health and safety, environmental, social and economic risks to the business • develop an emergency response plan • conduct and facilitate TMF audits according to the performance standard.

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OUR APPROACH TO RESPONSIBLE TAILINGS MANAGEMENT/ COMPLIANCE TO VEDANTA TMF STANADARD

Our Approach to Responsible Tailings Management describes how we responsibly managing tailings at Hindustan Zinc from both a governance and technical perspective.

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Rampura Agucha Mine

Rajpura Dariba Mine

Zawar Mines

TAILING MANAGEMENT POLICY & TAILING MANAGEMENT PLAN

TAILING STORAGE DESIGN

INCORPROATING BEST PRACTICES

SURVILLANCE OF TAILING DAMS

INTERNAL / EXTERNAL REVIEW

EMERGENCY PLANNING AND RESPONSE

RAMPURA AGUCHA MINE

RAJPURA DARIBA MINE ZAWAR MINE

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TAILING MANAGEMNT POLICY & TAILING MANAGEMEMNT PLAN

We have a dedicated policy on Tailing Management which guides us to manage tailings and Storage facilities in a manner that minimize the environmental, social and economic risk.

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TAILING MANAGEMENT PLAN

Tailings management plans are an essential prerequisite for sound storage practice as most failures of tailings storages around the world result from inadequate management of the storages. The effective implementation of a management plan will not only result in a safer tailings storage facility (TSF) but will frequently reduce the overall costs associated with operation and closure of the facility. All the three Mines are having Tailing Management Plan- OMS Manual. This Operations, Maintenance and Surveillance (OMS) Manual describes:

• Roles and responsibilities of TSF Committee (Governing Tailing Management) • Describes the engineering and design of the tailing facilities • Procedures and processes for operation & maintenance, construction, surveillance of the facility;

monitoring the components, their parameters • Emergency procedures

TAILING STORAGE DESIGN

Every location of our mines is unique and, as such, our tailings facilities are designed to consider a range of factors including the local topography and climate, the geotechnical, geological and seismic activity, its proximity to people and infrastructure, land rehabilitation, and future land use considerations.

There are three main tailings construction methods used at our facilities and are chosen based on the above factors and to ensure the safety and security of environment, nearby communities and other stakeholders:

• Downstream design continues the construction of the embankment wall on the external side of the compound with the batter extending on to what we call natural surface (or land that previously has not been disturbed), by depositing more support rock and bunding against the previously built tailings wall, thereby expanding the footprint, width and height of the initial embankment wall.

TSF COMMITTEE

There is Tailing storage facility committee at corporate level and at all the three mining sites which is comprising of representatives of various functions. By strengthening our governance model and clarifying the chain of accountability, HZL has recognized our in-house experts responsible for

• Creating Awareness on tailing management policy, standard, plan and best practices • Ensuring adherence of Operations, Maintenance and Surveillance (OMS) Manual • Ensuring effectiveness of reclaim water system • Ensuring effectiveness of Emergency Planning and Response • Ensure the availability of all required resources • Ensure Continuous monitoring and reporting

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• Centerline design involves the continuation of the embankment construction on the external side of the compound however, does rely on the deposited tailings adjacent to the top of the initial embankment wall to support the raises.

• Upstream design allows the embankment wall to be constructed on the inner side of the compound and relies on the strength of the deposited tailings to support the structural material for each lift of the embankment. This method allows for smaller quantities of earth and rock fill to be built on top of the tailings and therefore does not expand the footprint of the facility.

INCORPROATING BEST PRACTICES

The safe and responsible management of TSF is a core to our mining activities. Our management of these infrastructures include ensuring a high standard of care is applied at the design, construction, operation and closure stages of mining. Additionally, we are committed to continually improving the management of our facilities by developing and incorporating best practices like:

• Adopting a clear policy on tailings management and a strong commitment by management for the safe and

responsible management of TSF.

• Establishing TSF Committee – in house experts to strengthen compliance to Vedanta TMF standard.

• Selecting reputable engineering and design firms for the design of these facilities

• Conducting periodical TMF risk assessment and developing mitigation plan to minimize associated risks

• Tailings utilization in back filling through paste fill/ Hydro fill

• Replacement of wet tailing disposal system with dry tailing disposal

• Supernatant water is collected and recycled in process

• Garland Drains around Tailing Dam, Zero Liquid Discharge is maintained from tailing dam

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BEST PRACTICES

SUPERNATANT WATER COLLECTION POND

PASTE FILL PLANT

DRY TAILING PLANT

GARLAND DRAINS AROUND TAILING DAM

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SURVILLANCE OF TAILING DAMS

Surveillance involves inspection and monitoring of the operation, structural integrity and safety of a facility. It consists of both qualitative and quantitative comparison of actual to expected behavior. Regular review of surveillance information can provide an early indication of performance trends that, although within specification, warrant further evaluation or action.

1. Visual Monitoring and Inspection- Weekly/Monthly and annual monitoring of the impoundment, dam

safety instrumentation monitoring, and environmental monitoring by TSF committee

2. Geotech Monitoring on Tailing Dam- o Pillar-prism-total station data for measurement of Slope displacement

o Piezometer for measurement of pore water pressure

o Inclinometer for measurement of Sub-surface deformation

o Cameras are placed for security purpose monitoring

INTERNAL / EXTERNAL REVIEW

Internal

• Comprehensive internal audits/ inspection by cross-functional teams

• Hazard identification & risk assessment carried out and reviewed periodically.

External

• Engagement of world class consultants Indian Institute of Science (IISc), Bangalore and IIT Guwahati etc.

• Independent assessment by global experts Golder Associates to review the integrity/ stability of our dam

structures and their associated management practices

INCLINOMETER

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EMERGENCY PLANNING AND RESPONSE

The final key element in our approach to Responsible tailing management is emergency preparedness and response. All significant aspects of the economical, safe and environmentally responsible disposal and storage of tailings and management of water and related emergency preparedness plan are designed to be mitigate the risk. Emergency Preparedness and Response Plan available at all the three mines and is enabling us to identify emergency and hazardous conditions threatening the TSF, expedite effective response actions to prevent failure, and reduce loss of life and property damage.

Key features of Emergency Planning and Response are

• Identify emergency and hazardous conditions threatening the TSF; • Assessing, mapping and mitigating the potential impacts from a hypothetical failure scenario • Training and awareness to operations personnel in responding to emergency conditions; • Testing of effectiveness through validation drills

OUR PERFORMANCE: KEY INDICATORS OF PERFORMANCE IN TAILINGS MANAGEMENT AT HINDUSTAN ZINC INCLUDE:

o Zero incidents associated with existing tailings facilities.

o 100% of active tailings facilities have undergone independent third-party reviews in the last three years.

o No issues identified in site Tailings internal/ external review that would indicate potential risk.

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ANNEXURE-1 DISCLOSURE OF OPERATING DETAILS – OCTOBER 2019

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