Sustainability Report <SR> 2020

Environmental stewardship

“Effective stewardship of the environment is kept in focus as we work to meet business objectives.”


Our environmental stewardship activities are focused on managing the impact of our operations on land, water, air and energy resources. Our programmes are governed by the Group Environment Policy, Standards and Guidelines. A number of programmes were progressed, and others completed, during the year.

In common with many industries, the COVID-19 pandemic and subsequent national lockdowns and travel restrictions introduced changes to the status quo in the mining industry. Environmental authorisation processes were amongst those impacted, requiring our environmental staff to evolve innovative approaches to ensure that permits, critical for the continuation of operations, were obtained.

In Brazil, to limit delays in several licensing processes caused by travel restrictions on regulators conducting site inspections, the team worked with regulators to provide focused drone video footage of project areas. In Colombia, the National Environmental License Authority (ANLA), mindful of the limitations that social distancing has on public consultation around the Quebradona Environmental Impact Assessment (EIA), worked with us to overcome the challenge of holding traditional town hall sessions. This has included the design of virtual engagements, to be run in 2021, with the emphasis on ensuring equal access to all parties and that the legitimacy of the permitting process remains the absolute priority. In some cases, however, as was the case with Siguiri in Guinea, extended delays due to COVID-19 restrictions resulted in a few environmental permits expiring before the renewal processes could be completed. Despite the challenges, the Guinean environment regulator undertook a public consultation and site verification for the proposed Siguiri Block 2 mining project, granting the environmental permit within the anticipated timeframe.

Our environmental stewardship approach involves managing the impact of our operations on air and water resources and using natural energy resources efficiently. We also work to rehabilitate previously disturbed land and protect valuable biodiversity in areas where we operate. At site level, these management processes are governed by our Group Environment Policy, Standards and Guidelines. Each operating site’s environmental controls are implemented through its Environmental Management System (EMS), which is certified to the ISO 14001:2015 standard. COVID-19 travel restrictions also impacted on some sites’ EMS recertification processes, which in agreement with respective auditors, underwent virtual audits of their management systems to the extent possible, with field verifications to follow once travel restrictions are lifted. The combined assurance audits through which we assess conformance against our Environmental Standards were similarly impacted, resulting in remote reviews of an operation’s performance, also to be augmented once restrictions are lifted.

Despite the operational challenges, AngloGold Ashanti’s environmental teams continued to progress several initiatives through the year with a number of programmes completed. An example is our Obuasi redevelopment project in Ghana, where we developed an enhanced management operating system, clearly setting out the accountabilities and workflow maps in between the environment line functions.

Audits and certification updates

The pandemic had a varied impact on certification processes and audits throughout our operations.

  • Sunrise Dam’s Cyanide Code was successfully recertified.
  • An online International Organization for Standardization (ISO) surveillance audit was completed for the Generative Exploration unit.
  • At Cerro Vanguardia virtual follow-up audits of the ISO management system were performed.
  • Remote audits successfully completed at Iduapriem and Siguiri. Site verifications to follow.

Our performance

87% certified
to International Cyanide Management Code
94% certified
to ISO 14001:2015

Obuasi will initiate work towards ISO14001 and ICMI recertification during 2021

Reportable environmental incidents

Incident description
Immediate and corrective actions

On 16 January 2020, an engineering team at Siguiri mine was preparing to connect the new Tinkisso river water supply pipeline to the existing raw water pipeline at the Return Water Dam area, 1.7km from the Siguiri processing plant.

The team needed to drain the existing pipeline to complete the tie-in. Unfortunately, the tailings Return Water pipeline running alongside the existing raw water pipeline, was opened and drained for three hours.

The drained water, assumed to be raw river water, was directed to the nearby Diamon stream. The team was alerted to their mistake and immediate remedial action was taken.

Hydrogen peroxide was dosed to neutralise any potential residual cyanide in the process water and the stream was diluted with raw water from the Tinkisso River.

The nearby community was advised of the incident and community warders were stationed to prevent human and livestock access.

The Siguiri Environment Directorate was notified and invited to site for sampling and assessment.

Water quality sampling continued until the impacted stream was confirmed as being safe. Within four days, sample results showed complete dissipation of the impact downstream of the spillage location.

Power outages during mid March at Siguiri mine’s Wartsila power plant resulted in the overflow of the mills and various process plant tanks.

This occurred while construction to upgrade the plant’s pollution dam was underway and temporary spillage control infrastructure was being used.

An estimated 25m³ of the water being held in the temporary containment system, seeped through the slightly porous laterite wall, pooling outside the fenced area and was discovered during a security patrol.

Samples recorded contaminants higher than the IFC effluent standards.

The area was immediately barricaded, and samples collected and analysed.

Hydrogen peroxide was applied to the ponded water to neutralise any cyanide present and the water was pumped back to the plant.

On 5 June 2020, a leak developed on a section of Cuiabá mine’s tailings pipeline, located between the plant and the TSF.

Most of the material spilled onto the unpaved TSF access road, but despite additional measures to contain the spill with geotextiles, an estimated 5m³ entered the Cuiabá Creek via a system of stormwater ditches and sedimentation sumps.

Samples of the impacted stream found manganese and turbidity outside of compliance limits.

The residue pump system was stopped and work to repair the pipeline initiated.

In parallel with clean-up operations of the road and the stormwater drainage system, water quality and sediment monitoring downstream of the site was initiated.

Mine staff informed the environmental authorities and key stakeholders, including community leaders.

Monitoring of the watercourses showed the effect to have completely dissipated within two days.

Fine tailings material on the banks of the Sabará river was later cleaned up.

On 20 June 2020, a buried pipeline conveying impacted storm water from Obuasi mine’s dormant Pompora TSF facility, for treatment at the Pompora Water Treatment plant, was reported to be leaking.

An estimated 200m³ of impacted stormwater was released to the clean stormwater bypass canal running alongside the TSF and discharging into the Kwabrafo stream.

Subsequent investigation found that the pipe was likely damaged by earth moving equipment passing next to it, but being buried, the damage remained undetected until rain was being routed off the TSF.

Water samples taken at the incident site and downstream in the Kwabrafo river showed contaminants above the Environmental Protection Agency (EPA) effluent quality guidelines. However, throughout 2020, this has been characteristic of this part of the Kwabrafo river, in large part due to illegal mining disturbance in the watercourse.

A leak on Mineração Serra Grande’s tailings pipeline was detected by mine staff during inspections at the end of June 2020.

On evaluating the extent of the spill, it was discovered that released slurry had reached the Vermelho River via a natural drainage path.

Water sample results taken in the river did not detect any appreciable changes in its water quality.

Community and local authority representatives enquired about the incident and responses were provided by mine staff.

The pumping systems were immediately shut down and the leak was repaired.

The environmental authority and key stakeholders (including community leaders) were notified and the environmental agency visited the site on the subsequent two days.

Samples of water, soil and sediment were collected by the environmental agency authority and Serra Grande staff.

The mine was requested to provide the regulator with additional information such as water, soil/sediment analyses and findings from its internal investigation.

Following a 40mm rainfall event in mid July, on the Saddle 3 area of Siguiri mine’s TSF, a large volume of stormwater runoff accumulated against Saddle 3’s paddock wall. The paddock system is designed to contain runoff from the outer slopes of the cycloned TSF wall.

Static pressure from the standing water caused a rathole to form at the base of the paddock wall, allowing the stored water to be released onto the TSF perimeter road. This overwhelmed a secondary containment bund located outside of the TSF perimeter road and the spill continued beyond the TSF outer fence, onto community-owned cashew farms.

Water samples showed some contaminants were above the IFC Effluent Discharge Standards.

The impacted area was secured to prevent further discharge outside the TSF fence and to avoid any livestock accessing the spillage.

Detailed incident and geotechnical investigations noted the primary cause to be improper maintenance of the paddock containment system, which allowed water ponding in a single area.

The paddock was reconstructed with segments to prevent a recurrence and with facilities to regularly remove accumulated silt.

After searching for the source of sporadically elevated levels of contaminants in a nearby stream, on 30 July 2020, the Obuasi mine’s environmental monitoring team discovered a vandalised HDPE pipeline discharging water into a drainage system.

On investigation it was found that a ~3m portion of the pipeline had been removed and stolen by unknown person(s).

The source of the water was identified as a bypass stream from the water treatment plant, which intermittently directs excess process water to the mine’s Pond 3 facility, for temporary storage.

After the flow was stopped, the missing portion of the line was re-installed.

At the time, theft had been a significant issue on the mine footprint, with other materials being stolen from sites where construction was ongoing.

The incident was reported to the Ghana EPA who requested the mine to share its investigation outcomes, and recommendations on preventing similar incidents.

At the Obuasi mine during mid November, the crew of an engineering contractor was tasked with installing a new 400mm isolation valve on the South TSF return water pipeline.

The task required draining residual water from a partly opened flange on the pipeline, to a predetermined containment zone. However, when the supervisor left his crew to fetch some additional tools, they further opened the flange to increase the flowrate of the water being drained.

This resulted in process water overrunning the intended containment zone, and spilling an estimated 25m³ into a storm drain that leads to a natural wetland area.

Samples at the point of the release recorded contaminants in excess of the EPA guidelines. Fortunately, upstream and downstream analyses did not show a determinable impact from the event.

On discovery, the flange bolts were immediately retightened and the work halted. It was only recommenced after water levels on the TSF had sufficiently reduced and the pipeline fully emptied.

Approximately 75% of the water was pumped back from the concrete containment area to the TSF.

The need to ensure adequate supervision for all tasks and that they are executed to plan, was reiterated with all AngloGold Ashanti and contractor staff, as well as the need to consider potential environmental impacts during job planning.

Indicator 2020 2019 2018 2017 2016


Liquid fossil fuels (Kilolitres)
Group 270,063332,127318,102318,701289,345
Argentina 11,30215,25115,59118,76116,050
Cerro Vanguardia11,30215,25115,59118,76116,050
Sunrise Dam14,29212,80416,13914,19312,345
Tropicana2, 34762,74052,69852,00552,796
AGA Mineração15,90013,32211,16913,03711,224
Serra Grande6,4476,1965,2215,7045,494
South Africa1473781,8155,1865,260
Mine Waste Solutions2342,625165
Vaal River097761,7353,485
West Wits1473661,0368261,610
Lubricants (Kilolitres)
Cerro Vanguardia438439380414441
Sunrise Dam66416516472177
Brazil 1,2319999019541,025
AGA Mineração964775658698782
Serra Grande268224243256243
South Africa186293387801802
Mine Waste Solutions2028342918
Vaal River93269251319
West Wits72239344521465
Geita 1,2111,5221,43712361,152
Explosives (Tonnes)
Cerro Vanguardia3,1084,2853,5944,3684,005
Sunrise Dam2,2472,7891,1311,0492,060
AGA Mineração5,5994,1083,7664,3822,300
Serra Grande2,2601,8681,8991,4811,746
South Africa4346828411,6152,410
Mine Waste Solutions00000
Vaal River000479570
West Wits4346828411,1361,840
Cyanide (Tonnes)
Cerro Vanguardia1,0449951,0741,2781,072
Sunrise Dam1,6811,6261,5001,2021,244
AGA Mineração969738781878728
Serra Grande634572450548533
Guinea 6,0334,9793,1862,5082,378
South Africa7,26414,10611,84210,1229,672
Mine Waste Solutions5,1428,5818,8736,4306,349
Vaal River7843,7341,2701,9751,863
West Wits1, 3381,7911,6991,7171,460
Total acid consumption (Tonnes)
Cerro Vanguardia1,6262,0341,3701,9451,952
Sunrise Dam1,035623569571572
AGA Mineração1,5181,7521,5281,3361,798
Serra Grande4755721624
South Africa2,171 5,27412,66247,86154,589
Mine Waste Solutions757 1,2812,8114,3809,686
Vaal River158 2,7438,94642,69743,795
West Wits1,256 1,2509057841,108
Tanzania277 241189199178
Geita277 241189199178
Total alkali consumption (Tonnes)
Cerro Vanguardia2,0712,0212,3222,0832,083
Sunrise Dam18,99314,35813,7516,8119,581
AGA Mineração37,44515,06719,67821,25816,738
Serra Grande1,1621,2348911,6281,370
South Africa24,79341,02036,74053,98650,932
Mine Waste Solutions19,77227,93026,76524,82421,698
Vaal River2,2549,7166,30825,61326,387
West Wits2,7663,3743,6673,5492,847


Non-hazardous waste
Non-hazardous waste by type (tonnes)7,37314,81413,75520,77319,688
Recycled ferrous metal waste6,96314,25812,97319,94917,796
Recycled non-ferrous metal waste4095567828241,892
General waste (tonnes)25,14540,33833,01948,04358,477
On-site disposal21,30520,10931,03145,35044,243
Off-site disposal97318,7859708549,389
Hazardous waste by type
Battery waste (Tonnes)949140361110
Off-site disposal1940.021
Hydrocarbon waste (m³)3,968**1,4442,9743,7865,162
On-site disposal0000327
Off-site disposal1,7212289321,4952,843
Other hazardous waste incl. fluorescent lighting and chemical and solvent waste (Tonnes)18,56925,33023,80331,37724,689
On-site disposal17,44024,22522,77630,57723,849
Off-site disposal15824829897226
International Cyanide Management Code certification
Number of processing plants certified in full compliance to the international cyanide management code1413141715
Percentage of processing plants certified in full compliance to the international cyanide management code8887939483