Vale Dam Audits – Monthly UpdateMPMG, ANM and MPT

November 6, 2020

1

SLR.GEN.0029

Dams at Emergency Levels

2

No changes from September• Emergency Level 3

• B3/B4 • Emergency Level 2

• Doutor• Emergency Level 1

• Campo Grande • Dicão Leste• MAC B5 • MAC B6• MAC B7A• Maravilhas II • Mutuca B5 • Paracatu• Taquaras • Vargem Grande

Mar Azul - B3/B4 Dam

3

• Emergency Level 3 since March 2019

Reservoir

PDE XPDE Oeste

Dam B4

Dam B3

Reinforcement Berm - 2018

B3/B4 – Progress

4

• Backup Dam Gate completed Closing time tested and video received by SLR Spillway raise completed

• Dam Break Study Fugro report submitted & audit nearly completed Potamos declined peer review All tailings and runoff during tailings flow is contained SLR is requesting more detail on flow through spillway

• Slope maintenance PDE Ouest slope regraded before rainy season

Gates

B3/B4 – Progress & Priorities

5

• Decharacterization Additional radar monitoring installed to close SLR recommendation Lifeline testing and training completed, SLR auditing emergency plan Operating manual audit completed by SLR

• Priorities Commence PDE X excavation Finalize Dam Break Study reporting Second lifeline will be completed in November Install piezometers for pump tests monitoring

Mar Azul Taquaras Dam – Progress & Priorities

6

• Emergency Level 1 since April 30, 2020• Progress

Upstream slope earthworks completed Upstream slope revegetated

• Priorities Geotechnical investigations As-Is update

Timbopeba - Doutor Dam

7

• Emergency Level 2 since April 1, 2020

Doutor – Progress & Priorities

8

• Progress As-Is report with new investigations Doutor Dam mid-slope berm proceeding well Spillway construction:

– access road 84% / excavation 18%

• Priorities Revise As-Is Better documentation of geology in spillway excavation

Aboboras - Vargem Grande Dam

9

• Emergency Level 1 since March 2019

Vargem Grande – Progress & Priorities

10

• Progress Channel excavation on tailings beach

(remotely operated equipment) Removing tailings from upstream cells Interpreted dam stability with new

piezometers

• Priorities Complete rain season preparation – Vale

& TPF (Engineer of Record) requested the use of manned equipment to increase productivity

Develop a decommissioning plan for water level indicators that do not function properly

Agreement on the Factor of Safety

Fernandinho Dam

11

• Normal condition (no emergency level)

Fernandinho Dam Decharacterization

12

• Progress Decharacterization 37.5% complete Deformation monitoring system improved, new reference station

Tamandua - Capão da Serra Dam

13

• Progress Former spillway remediation in progress

• Priorities Structural improvements to spillway in

the right abutment

Alegria - Campo Grande Dam

14

• Emergency Level 1 since July 2019

North/South Dyke

Main Dam

Saddle Dyke I

Campo Grande - Progress

15

• Progress Basic design of decharacterization completed

• Priorities Vibration test for Campo Grande and Xingu (Alegria Pit) SLR recommended vibrating-wire piezometers

Pico - Maravilhas II Dam

16

• Emergency Level 1 as of September 2019

Saddle Dyke II

Main Dam

Saddle Dyke I

Maravilhas II - Progress

17

• Progress Reservoir pumped lower than 2019/2020 rainy season Piezometer live-tests completed New seismographs installed (5) Downstream slope cracks healed with rains (supports shrinkage crack theory

• Priorities: Advance reinforcement design

Pico - Maravilhas III Dam

18

• Emergency Level 1 as of September 2019• Progress (dam under construction)

Foundation jet grouting test completed Right abutment cracks repaired

• Priorities Report on crack repairs scheduled for November

Mutuca - Dam 5

19

• Emergency Level 1 since July 29, 2020• Progress

Trenched at crest to confirm (for As-Is)

• Priorities As-Is and piezos delayed for drilling

Águas Claras - Dam 5 / Auxiliar Dyke

20

• Dam 5 / Auxiliar Dyke Emergency Level 1 since April 1, 2020

• Progress Dam 5 / Auxiliar Dyke Pump cable replaced and security

improved to prevent theft Dam break study completed for

SLR auditing

B6/B7A New stairways for inspection /

surveillance

Dicão Leste Dam

21

• Emergency Level 1 since May 8, 2020• Progress

Erosion protection (biomanta) on crest

Paracatu Dam

22

• Emergency Level 1 since May 8, 2020• Progress

Temporary spillway design completed and audited

• Priorities Install temporary spillway Commence spillway upgrade

Obrigado

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