9 – RECOVERY OF THE RESERVOIR OF THE HYDROELECTRIC PLANT RISOLETA NEVES
Objective of the program
Restoration of the operating conditions of the Risoleta Neves Hydroelectric Power Plant by means of implementation of actions of silt removal in the flood area of hydroelectric dam and infrastructure repair.
Completed the restoration of the Floresta Farm Silo.
The contract transfer processes from the Renova Foundation to Samarco is underway.
In the Environmental Program for monitoring vibrations, no event was identified with a value above that established by ISO/2631/DAD1 (1980).
In the Environmental Noise Monitoring Program, no event was identified with a value above that established by State Law 10.100/90 for Rural Residential Areas.
SEMAD granted the licensing for the LOC Corrective Operation for Environmental Regularization of dredging works and disposal of tailings at the Floresta Farm and recovery of margins and sectors (HPP RISOLETA NEVES).
Cooperation agreement between Renova Foundation and Samarco signed.
Construction works for the Rainfall Plan underway as scheduled.
Construction works for rehabilitation of UG1 are under way, with 52% of progress.
Noise monitoring program presents figures within the limits established by state law 10.100/90 for rural residence areas.
Candonga licensing ICs filed with the SUPPRI.
Virtual public hearing for the Candonga licensing process was held.
Actions to respond to the ICs regarding the Environmental Impact Study (EIA) in progress, with a tendency to be referred to SUPPRI within the stipulated period.
UG1 rehabilitation activities are underway.
The intention of transferring the PG09 to Samarco was communicated to CIF.
Rainfall Action Plan works in progress according to schedule.
Sensors installed on Barrier B already show first results.
Field activities paralyzed since March 20th, due to the coronavirus pandemic.
* Dredging, dewatering and treatment projects being developed.
* Program of Correction of anomalies of geotechnical structures underway and already shows the first positive results.
* Maintenance services performed (correction of the overflow channel, cleaning of access and channels).
* Additional information in the licensing process requested by SUPPRI
* Monitoring of instruments and structures, showing that the geotechnical structures of PG09 present adequate stability conditions.
* Due diligence and handover to Samarco in progress. Final report from the Samarco team on 31/07, accepting the transfer of the program.
• Field activities have been suspended since March 20 due to the coronavirus pandemic.
• Dredging, dewatering, and water treatment projects are being prepared.
• Program for correcting anomalies in geotechnical structures is being implemented and is already showing its first positive results.
• Maintenance services performed (correction in the spillway canal, and cleaning of access roads and rain gutters).
• SUPPRI requested additional information in the Licensing Process.
• Monitoring instruments and structures, showing that the geotechnical structures of program PG09 have adequate stability conditions.
• Due diligence and handover to Samarco in progress. The final opinion of the Samarco team on 07/31, accepting the transfer of the program.
• Field activities have been suspended since March 20 due to the coronavirus pandemic.
• Due diligence and handover to Samarco in progress, finalizing the submission of documents and meetings between focal points. Samarco’s team is analyzing the documents.
• Contracted the supplier for the restoration of the Floresta Farm and started revitalization works. Projects for the Floresta Farm were presented.
• Dredging, dewatering and water treatment projects are being prepared.
• Judicial determination forwarded to the Candonga Consortium requesting information on the authorization for land surveying. Consortium responded with a Technical Note scheduled for 10 days (expected for 07/01/20).
• Maintenance of access roads (main access and slope correction along the road to the Marimbondo Community) and maintenance of the basins (cleaning, weeding, and mowing).
• Updated the Licensing Status (Environmental Impact Studies - EIA) using the prepared flowchart.
• Monitoring of instruments and structures, showing that the geotechnical structures of program PG09 have adequate stability conditions.
• Field activities have been halted since March 20, 2020, due to the coronavirus pandemic.
• Based on approved decision trees for resuming services, the following fronts were allowed to resume activities: pile 01, construction site assembly, slopes downstream from the dike, access maintenance, and geotechnics.
• Starting the restoration of the Floresta Farm, mobilizing the contractor's team shortly after the kick-off meeting.
• Preparing strategic planning, considering the main issues related to the Program, such as: Licensing, Geotechnical Structures, Dredging, Due Diligence, etc.
• Dredging, dewatering, and treatment projects are in preparation.
• Removing remnants from construction sites and storing them in Sector 11.
• Creation of a reforestation schedule (PRAD - Plan for the Recovery of Degraded Areas) for the Environmental Management Program, considering two stages: the 2020/2021 wet season and the wet season following the completion of dredging.
• Responding to questions from the Candonga Consortium regarding the addition to the basic project and the signature of the Consortium's contract addendum with the company Intertechne regarding Package 4 (where surveys are included).
• Performed access maintenance and mowing the main access roads.
• No anomalies compromising structural stability were found while monitoring instruments and structures according to the monitoring schedule.
• Delivery of Sector 8.
• Field activities have been suspended since 03/20/2020, due to the coronavirus pandemic.
• Plans for the resumption of each front were presented and are under evaluation by the Renova Foundation. Fronts already allowed to carry out their activities: Cesbe emergency patrol, Mayrink Neto emergency team, and aerial survey.
• Elaboration of scenarios for post-pandemic planning, considering: Licensing, Package 1 (works required for dredging, for filling the reservoir and other infrastructure works), Package 2A (sediment dredging), Package 3 (rehabilitation of the Hydroelectric Power Plant - recovery of the Generating Units) and Filling Plan (reinforcement blocks).
• Performed access maintenance.
• Mowed the main access and weeded around drains.
• Project for the execution of the headwalls for the wheel washing station and fence for the reconstructed area.
• Raised the lower part of the reservoir that contributes to the Micaela stream.
• Monitoring of instruments and structures according to the monitoring schedule.
• Improvement works in Sector 8 have been completed.
• Authorization for external drilling at the HPP to prepare the executive project to reinforce the blocks.
• Characterization of the fractured environment to understand the direction of the fractures, which may represent preferential paths for groundwater.
• Verification of the piezometers positioned downstream from the dike of sector 4, which present greater loads than those upstream.
• Mobilization of CESBE in progress.
• Maintenance of accesses.
• Completed plantation of signal grass in Sector 8.
• Studies carried out for the implementation of downstream protection of Barrier C and the restoration of erosions that occurred on the right and left banks of the river in this region.
• Improvement works have already taken place on the following fronts listed in Descriptive Memorial - Floresta Farm TAC: pile 01 (partial), adequacy of basin 2A, spillway of basin 2B, decommissioning of sector 01, decommissioning of sector 05B, points 91 of margins, experimental landfill, temporary pile, slope downstream of the main dike and Corsini quarry.
• Presentation in court of the petition regarding the process for formalizing the environmental licensing of Candonga, including all the documents specified in SUPPRI's Legal Note.
• Inspection of the infiltration basin and sanitary sewer where it was found that the volume of material deposited has reduced, namely: infiltration basin 30.0m³ of waste, sanitary sewer 12.2m³ and auxiliary pit 1.0m³.
• Installation of the construction site for the renovation of the HPP has been completed.
• Field activities were suspended on 03/20/2020 due to the new coronavirus pandemic.
• An inspection was carried out by the company Andritz at the facilities of the Risoleta Neves Hydroelectric Power Plant, where no additional irregularities were found in relation to the items already diagnosed. Field activities will begin in March 2020.
• Recovery of the left and right shoulders of barrier C that were impacted by the rains.
• Recovery of access to barrier C that was impacted by the rains.
• Maintenance of damage to the spillway cause by the heavy rains.
• Maintenance of the gabion wall of basin 2A.
• Continuity of construction of gabion wall in basin 2B and basin 1.
• Maintenance of surface drains in sector 11.
• Installation of fence and bioengineering in sector 08.
• Bioengineering at point 166.
• Commencement of the mobilization of the company CESBE for infrastructure work services.
• Cleaning downstream of the headwall in sector 4 after heavy rain.
• Continuity of construction of gabion walls in basin 1 and basin 2B.
• Completed the gabion wall reinforcement in basin 2A.
• Bioengineering of slopes that were exposed in sector 8.
• Bioengineering at points 164 and 165.
• Construction of compacted landfill at point 116.
• Bioengineering at points 156, 157 and 166.
• Completed dredging of the spiral casing of Generating Unit UG1.
• Kickoff Meeting (KOM) was held with the company Andritz to start the rehabilitation works of the generating units, with the participation of Aliança, The Renova Foundation and Candonga Consortium.
• Slope restoration and drainage maintenance in sector 8.
• Completion of internal cleaning of the suction tube of Generating Unit 02.
• Drainage of Generating Unit 03.
• Completion of the Fire Fighting Protection System (SPCI) readjustment works at the Hydroelectric Power Plant.
• Addendum to the basic project filed with the Consortium Candonga 100%.
• Resumption of the dredging actions, scheduled for 2019, did not take place. Causes: Change in the volume to be dredged and in the engineering of the dredging process. Countermeasures: Complete study of the volume to be dredged and define which strategy to be used to remove the tailings.
• The decommissioning of sectors, recovery of margin points, containment of tailings structures and effluent treatment at the Floresta Farm, scheduled for 2019, have not been completed. Causes: New engineering solutions have been defined for the decommissioning of the sectors, recovery of margins and removal of tailings after the collapse of the Brumadinho dam (MG), with the publication of law No. 23.291, of February 25, 2019, requiring licensing for dams that have the following characteristics: I - height of the massif structure, counted from the lowest point of the foundation to the crest, greater than or equal to 10m (ten meters); II - total capacity of the reservoir greater than or equal to 1,000,000m³ (one million cubic meters). Countermeasure: Contract company through RFP to perform infrastructure services in 2020, starting after the rain plan is in place.
• Cleaning of the generating units of the Hydroelectric Power Plant (HPP), scheduled for 2019, has not been completed. Causes: Encountering difficulty in removing the heterogeneous material deposited within the generating units, pumping equipment, inaccurate estimations of the volume to be cleaned and the methodology initially implemented were not the most efficient. Countermeasures: Request a contract addendum from the company Allonda so that the cleaning services of the generating units at the HPP can be carried out in two shifts and lease specific pumps for the dredging of tailings (concluded).
• Alignment of metal profiles, positioning of pre-welded plates and assembly of frames for the execution of the bridge in Rio Doce/MG.
• Slope Restoration and Drainage Opening - Sector 8.
• Execution of the anchored wall at point 115 is in progress.
• Preparation of the topographic plan of the area where the Urban Park will be built in Rio Doce/MG.
• Slope of stoplog 2 of Generating Unit - UG1.
• Continued cleaning of the forced duct and spiral casing of Generating Unit - UG2.
• Completed drainage of spiral casing of Generating Unit - UG3.
• Drainage of the suction tube in the Generating Unit - UG3.
• Dredging of Stoplog 3, cleaning and blasting of spiral casing of Generating Unit – UG3.
• Initiation of execution of the gabion wall in Basin 2, in compliance with the 2019/2020 rainfall plan.
• Reinforcement of Barrier C was halted on October 25 and work resumed on November 7.
• Monthly Safety and Environment dialogue with all employees involved in the construction of the Multifunctional Center - Rio Doce/MG.
• Application of geotextile fabric on internal slopes of basin 2A.
• Execution of small Wastewater Treatment Stations, “mini-WWTPs” and “retention basins” on properties along the Lajes Stream/MG.
• Emergency drill in the community of Merengo - Santa Cruz do Escalvado/MG.
• Emergency drill in Santana do Deserto community - Rio Doce/MG.
• Performed Kickoff with company Allonda for execution of the stability report and documentation of the Mining Dams Emergency Action Plan (PAEBM) of Sector 4.
• Continuity of activities related to the rainy season 2019/2020: drainage cleaning, mowing, weeding and maintenance of the sectors - Mayrink Neto/Piacentini Companies.
• Completed the cleaning of Generating Unit UG-02.
• Initiation of surveying of houses to be recovered in Santana do Deserto.
• Continued execution of item 115 by Progeo.
• Initiation of construction of the new bridge in Rio Doce, near the Town Hall.
• Execution of small wastewater treatment plants, “mini WWTPs” and “retention basins” on properties crossed by the Lajes Stream.
• Completion of cleaning activities in SUMPs of sector 11 (Pumping System).
• Completion of basin drainage 2.
• Initiation of works for internal reinforcement of basin 2.
• Completion of the installation of Rainfall Stations in sector 11 and in Areal.
• Completion of stoplog 01 groove repair and installation of stoplog floodgate of Generating Unit UG-01.
• Continuity of cleaning of the forced duct and spiral casing of Generating Unit UG-02.
• APRO approval for contract addendum and inclusion of teams for simultaneous work and two pumping shifts.
• Review of operational procedure for completing the cleaning of the suction tube using diving teams.
• Completion of the Fire Fighting Protection System (SPCI) readjustment works at the Risoleta Neves Plant.
• Installation of monitoring instruments in sector 8 by the Fugro company.
• Continuity of activities related to the rainy season: drainage cleaning, mowing, weeding and maintenance of the sectors by the companies Mayrink Neto and Piacentini.
• Reinforcement of barrier C remains paralyzed and awaiting definitions by SEMAD (State Department of Environment and Sustainable Development).
• Completion of cleaning of the water intakes and installation of the new stoplog sets of UG-01 Generating Unit.
• Beginning of installation of guide plate for repair of grooves of stoplog 01 of UG-01 Generating Unit.
• Continuity cleaning services of UG-02 Generating Unit.
• Continuity of works to improve the Fire Protection and Fire Fighting System at the Risoleta Neves Plant.
• Continuity of rainy season activities: drainage cleaning, mowing, weeding and sector maintenance - by Mayrink Neto / Piacentini Companies.
• Verification and maintenance of monitoring instruments throughout the construction.
• Lease of the polygonal terrain for verification of plant suppression at points 147 and 148.
• Demonstrations by the community prevented the team from accessing the work site for 21 days. Access was released on 09/18.
• Stoppage of reinforcement of Barrier C by SEMAD (State Department of Environment and Sustainable Development).
• Cement grout injection on the right shoulder - Barrier C (Piacentini Company).
• Completion of ADME 02 topographic surveying (surplus material storage area).
• Completion of margin recovery works at point 115.
• Beginning of rainy season activities: drainage cleaning, mowing, weeding and sector maintenance - Mayrink Neto / Piacentini Companies.
• Verification and maintenance of monitoring instruments throughout the construction.
• Planimetric and altimetric surveying of the Tapera district continues.
• Issuance of work order (OS) for execution of margin recovery points 119, 120, 147 and 148.
• Beginning of drainage of basins 1 and 2 in preparation for the rainy season.
• Verticalization of the floodgates of the water intake and final adjustments of the seals, whereas the Candonga Plant remains responsible for closing the floodgates of the water intake.
• Completion of the groove removal from the guide of Stop Log L02. Concreting will start after the Spec company elaborates the submerged concreting specification.
• Cleaning of the UG-02 suction tube (internal cleaning) continues.
• Drainage of the UG-03 was completed, with the proper functioning of the downstream floodgate seals.
• Completion of surveying of the wheel washing station and continuation of sampling at 400 m from the Risoleta Neves Plant.
• Implementation of speed reducers and warning signs in the 800 m section from the beginning of the MG-120 junction stretch to the wheel washing station.
• Community demonstrations prevented workers from accessing the site on August 29, 30 and 31.
• Issued work order for the company CESBE to execute the infrastructure of Sector 11 (Floresta Farm). Mobilization planned for August/2019.
• 800m of Hot-mix asphalt concrete (HMA) was used for pavement of the main access road BR MG-120 to the Wheel Washing Station.
• Completed cleaning of Stop Log 01 and 02 of the UG03 Generating Unit.
• Started cleaning the suction tube of UG-02 (Internal Cleaning).
• Receipt of the vertical log gates for the stop log floodgates of the Risoleta Neves HPP water intakes.
• Drainage of UG03 Generating Unit.
• Meeting for presentation of the company CESBE to the municipal governments of Santa Cruz do Escalvado and Rio Doce for definition of local contracting strategy.
• Implementation of monitoring marks on the right and left margins of the "C" Barrier.
• Implementation and tracking of "A" Barrier monitoring marks.
• Cleaning and maintenance of drains in Sector 11.
• Meeting with SEMAD (State Department of Environment and Sustainable Development) and TB of Tailings to understand the issuance of the Corrective Operation Permit (LOC).
• Defined by the Renova Foundation's maintainers and board of directors to protocol the official Work Schedule of Program PG-09 - Risoleta Neves HPP Restoration, disregarding SEMAD's understanding and assuming that the TAC allows for initiation of works this year.
• Presentation of the project of PG-009 - Risoleta Neves HPP Restoration - and official work schedule to CIF and the Technical Boards of Infrastructure and Tailings Management.
• Register boreholes in stack 1 and stack 2 in Sector 11.
• Resumption of activities on the Candonga site due to the discontinuity of demonstrations in Rio Doce and Santa Cruz do Escalvado as of 07/22.
• Community demonstrations prevented workers from accessing the works (right bank) for 15 days in July.
• Kickoff meeting (Package 01) with the company CESBE. Mobilization of the company is scheduled for July/2019 for initial execution of the infrastructure of Sector 11 (Floresta Farm).
• Drilling of an artesian well at the soccer field in Santana do Deserto.
• Beginning of the forest inventory work for installation of the sewage system of the WWTP in Santana do Deserto.
• Cleaning of the grooves and commissioning of the upstream floodgates of the Generating Units.
• Beginning of onboard surveying and continuation of surveying in the dewatering area (coffer).
• Defined coordinates for drilling the artesian well of the new Renova Foundation construction site.
• Demonstration by the community prevented the team from accessing the work site for 15 days.
• Hiring of company to execute Package 1, with work scheduled to start in June/2019.
• Drainage and opening of the hatch to perform cleaning of the suction and forced conduit of the Generating Unit (UG2).
• Continued cleaning of the grooves and commissioning of the upstream floodgates of the Generating Units.
• Continuation of drilling in the dewatering area (coffer).
• Initiation preventive inspection in Santana do Deserto. Six houses and the church were visited by AECOM, PROGEN, H&P, RETA and Civil Defense teams.
• Relocation of the electricity grid of Sector 08 by the company ENGELIG.
• Authorization by the Municipal Government of Rio Doce to drill the tubular well for human consumption in Santana do Deserto.
• Demonstration by the community from 05/09 to 05/20 withheld the team from accessing the construction site.
• Decommissioning of Draga B50 and HDPE drainage pipes by Allonda.
• Cleaning of the grooves continued and commissioning of the upstream floodgates of the Generating Units.
• Presentation of the plan for sediment removal in Sector 4 by Engineering (Walm). The solution was analyzed and commented on by the Construction team and is under analysis by Engineering.
• Presentation of the plan for the decommissioning of the Corsini Quarry by Engineering (Walm).
• Receipt of projects by Engebio for reforestation of the Floresta Farm (under analysis by the Construction team).
• Presentation of Conceptual Projects of Military Headquarters and Physiotherapy Center by the Municipality of Rio Doce. The Physiotherapy Center project was approved. The Quartel project was commented on by the corporation and will be reviewed by Engineering.
• Review of RT of package 1, consolidating the Masterplan and detailed planning of the Candonga complex.
• Completion of drillings in the Basins and initiation of drilling in the dewatering area (coffer).
• Initiation of SPEC's ATO activities to analyze and understand the demands for resumption of drainage activities by UG2, including review of procedures and supervision on site.
• Survey of potential points for the implementation of ADME (area of disposal of surplus materials). Evaluation of environmental performance of contractors in April.
Dredging of 959,382 m³.
Installation of three sheet pile structures within the Doce River Bed (Metallic Barriers A, B and C) that are under monitoring. There were 533 property inspections (86%), of the total estimated 621 properties mapped up to 02/28/19. Completion expected by 03/29/2020.
Installation of structures for treatment of effluents (Basins 1, 2A and 2B).
Installation of structures for rainy season at the Floresta Farm / Sector 11.
32 point were delivered, of the 79 points expected for recovery of the banks of the reservoir.
Monitoring and inspection of structures: Barrier A, Barrier B, Barrier C, Sector 4, Corsini Quarry, Basin 1, Basin 2 and Main Dike.
Execution of drainage system for flow measurement in Sector 8.
Installation of monitoring system (posts and equipment) for placing cameras on site.
Completion of works: renovation in the buildings of the Floresta Farm; recovery of banks, stacking of barrier A and cleaning of the HPP (installation of upstream and downstream stoplogs).
Inspection of the houses in the municipality of Santana do Deserto (MG).
Field visit and meeting with SEMAD and IBAMA and authorization to maintain Basin 1 as a security system structure.
Review phase of the technical and commercial proposals of the proponents of the infrastructure works (Package 1) for the Floresta Farm Complex.
Elaboration of the technical documentation (QQP and RT) to contract the works for the dredging system of the HPP reservoir.
Elaboration of the technical documentation (QQP and RT) to contract the automation works for the WTP and transshipment in the municipality of Rio Doce (MG).
Signing of the TAC with SEMAD on 02/18/2019.
Definition of the engineering solution for the main dike area, natural dewatering system and resumption of dredging.
Municipality of Santa Cruz do Escalvado: meeting held on 05/12/18 in which a preliminary evaluation of the lawsuits was made and the Renova Foundation requested more detailed information to proceed with the analysis. It was defined that the Foundation and the municipality will work together on the details of the lawsuits (working group). Inspection at the WWTP (Wastewater Treatment Plant).
Meeting with Commission of Affected Parties on 12/11/18 in which the Renova Foundation spoke on the progress of the activities developed in the Program.
ComeSee project in Candonga: first meeting was held in Candonga with the participation of the community of Santana do Deserto.
Cleaning of the dikes and silted SUMPs (containment basins), improvements to rainwater drainage structures (sector 11), reforestation works in Floresta Farm buildings, installation of outdoor lights, recovery of margin 115, root piling at barrier A and installation and assembly of equipment for cleaning the Hydroelectric Unit.
The Renova Foundation visited the Rio Doce/Novo Soberbo Water Treatment Plants to conduct a diagnosis for possible improvements in the process.
Completion of activities to prepare for the 2018/2019 rainy season. Completed works: installation of pumps and pipes in the region of the Tailings Heap; provisional spillway; drainage of the Disposal area; protection wings of the right shoulder of Barrier A (provisional solution); SUMPs and drainage of the Corsini Quarry.
Monitoring of structures in initial phase of operation.
Visual inspections were carried out in six houses considered critical in Santana do Deserto. It was concluded that there were no stability risks for the rainy season. They will be monitored over this period so as not to pose a risk to the community. A specialized company is being mobilized to carry out technical inspection of these buildings.
The access to the Rio Doce football field is being improved.
In Rio Doce, support and emergency interventions were provided due to the rains that occurred in December.
In progress, project to restore the main building of the Floresta Farm.
Activities of the 2018/19 rainy season action plan that were finalized in November/18: recomposition downstream of Barrier C; drainage of Sector 8; bioengineering in the region between dikes; Sector 04; service works in the tailings disposal area - Stack 01; Reno mattress and riprap at the shoulders of Barrier C; second stage of counter-stacking in the area of the intermediate dike; installation of pumps and pipes in the experimental landfill region and main dike.
Emergency evacuation simulation with the communities of Santana do Deserto (Rio Doce) and Merengo (Santa Cruz do Escalvado) on 11/10.
Resumption of biweekly meetings between the Renova Foundation and representative of the Rio Doce Municipal Government to align and update the demands.
Works to complete the actions of the rainy season plan at the Floresta Farm are under way. The main challenges are the temporary spillway and the construction of the wings for protecting the right shoulder of the A-Barrier, which are expected to be completed in Nov/18.
Some construction works that were completed in October/18 are: dyke for fine material containment (dyke 1.B / Stack 1); wet walkway; main dyke up to 366m; plotting of experimental landfill; monitoring of Barriers A and B; SUMP Experimental Landfill; 1st stage of back-to-back stacking; pre-modelled spillway; Micaela dyke; resloping of the right shoulder of the intermediate dam.
Preventative emergency simulation on 10/03, testing emergency sirens of the Risoleta Neves HPP.
There were demonstrations on September 17, 24, and 25, blocking the access to the construction area, impacting the overall schedule and completion of activities for the rainy season.
Exploration activities of Corsini Quarry resumed on 09/17, after been put on hold by DNPM on 08/29.
The actions of the plan for the 2018/2019 rainy season are still ongoing.
There were demonstrations on August 13, 14, 15, 21 and 22, blocking the access to the construction area, impacting the overall schedule and completion of activities for the rainy season plan. DNPM suspended the mining activities at the Corsini Quarry which was acquired by the Renova Foundation for supplying stone. A meeting with the agency is scheduled for 09/06. The actions of the 2018/2019 rainy season plan are already being implemented.
07/01 - Initiated the process for crushing stones extracted from the Corsini Quarry at the Floresta Farm. The material is being used as rockfill for the Main Dike.
07/10 - The Plan for filling the Risoleta Neves HPP reservoir was filed with the CIF and the Technical Board of Tailings.
Intermediate Dike - Clarification for public agencies and communities:
After the occurrence of the geological failure in the left shoulder of the intermediate dyke, there were questions * from the Association of Affected Parties of Barra Longa about a possible rupture of a structure of the Floresta Farm, causing sediment leakage in the area.
Actions of the Renova Foundation to provide clarifications to the community and public bodies:
✓ an official letter was sent to the Association of Affected Parties of Barra Longa, Government of the State of Minas Gerais and SEMAD with clarifications regarding the rupture on 07/24/18;
✓ monitored technical visits were made to the Floresta Farm on 7/24 and 7/25, 2018, by representatives of the Foundation, SEMAD, Rio Doce Civil Defense, Fire Brigade and Commission of Affected Parties of Barra Longa, and there were no further questions;
✓ release of a clarifying note that will be published in the week of 07/30 to 08/03, 2018, in newspapers and on the Foundation's website.
This month, the radar system was installed for monitoring the stability in the intermediate and main dikes. A geophysics team was also mobilized for this work.
In June, the dredging volume was 15,755m3 for sector 5. The amount foreseen according to the time frames was 20,000m3.
In the main dike, the activities continued for raising it with blocks to reach elevated levels of muddy material. This action is needed so that the works on the Floresta Farm are not affected during the 2018-2019 rainy season. In addition, the mud landfill is still kept closed until the necessary conditions are established.
This month, it was also necessary to shut down the works due to safety reasons, due to the instability and recording of cracks in the left shoulder of the intermediate dike.
The team formalized, together with the Technical Board of Tailings and Environmental Safety, the beginning of the dredging works for basin 2 at the Floresta Farm. The action meets the time frame that was filed in May 2018.
In June, activities were also carried out to recover points along the banks of the reservoir.
The decommissioning works of sectors 3 and 4 are also underway.
The planning and definitions for the Candonga Project indicators were protocolized on May 24 at the Tailings Technical Board and at the CIF. However, two issues are still pending: the Reservoir Filling Plan, which will be consolidated by July, and the decommissioning of Sector-4, which will be completed after the reservoir is filled.
The contracting of a company to rehabilitate the Hydropower plant’s generators is in progress. Licensing conditions also continue to be composed alongside the Doce River Municipal Government.
Works on the intermediate dyke’s left shoulder, however, needed to be temporarily halted. The activity demanded higher excavation and, consequently, higher filling/clumping in the future. Therefore, it is imperative to wait for new geotechnical data and for a new solution, pursuing a pumping alternative that does not require an intermediate dam. The launch at the main levee continues to advance.
On May 4, the water turbidity reading system was repaired, allowing the study of the new turbidity trigger to start. The solution will soon be proposed to the Tailings Technical Board.
Geomembrane has also begun being applied to Basin 01 - a necessary step before dredging for the Floresta Farm starts.
The decommissioning of sector 5C (part of sector 5) is in its final stage. Sector 5 will still receive dredged material in June.
The instrumentation for Barrier C is also completely installed, which makes it possible to read and monitor the structure’s stability.
The provisional polymer plant was also completed. This plant is responsible for treating the effluent that will return to Doce River. This will allow dredging to Floresta Farm by June.
In addition, works on the implementation of the Wheel Washer system began on May 18.
Dredging services in sectors 1 and 5 (phase 1) reached a total dredged volume of 21,200 m³. The initial volume prediction was 17,000 m³.
A meeting was held with the State Department of Environment and Sustainable Development of Minas Gerais (Semad). During the meeting, it was defined that there will be separate licensing to authorize plant suppression.
Construction of the embankment of Main Dike began.
This month, the communities of Santana do Deserto (Rio Doce), Merengo (Santa Cruz do Escalvado) and Biboca (Sao Jose do Goiabal), located downstream of the Risoleta Neves Hydroelectric Power Plant (Candonga), participated in evacuation simulations. In addition, isolated properties received door-to-door visits. Besides safety guidelines for emergencies, owners received informative materials.
The volume of rain registered in March was above the historical average, impacting the deadlines of the activities. The expected volume of dredged tailings in Phase 1 (sector 1 and 5) in March (36.7 thousand m³) had to be reprogrammed to 5,902 m³. The final services of barrier C were also reprogrammed, and the time frames are currently being revised collectively, with the Candonga Consortium, IBAMA, State Department of Environment and Sustainable Development and Technical Boards of Engineering, Construction and Tailing.
The time frames were analyzed, focusing on the risks associated to the planning of the works for the Restoration of the Reservoir, using the Range Analysis technique. A second round is already scheduled for March, using the same method.
As part of the competitive process for the acquisition of mobile equipment and the contracting of dredging inspection services, technical field visits were carried out and it is expected that in March the purchase requisition and order of these services to be contracted will be send to the selected companies.
Studies were started for breaking and crushing rocks in the Corsini Quarry, for the construction of the intermediate and main levee dikes, since the quarry at the Floresta Farm proved to be unexplorable.
The company that will operate the polymers plant is being mobilized.
The services for waterproofing the Basin 01 with geomembrane were contracted and the sourcing of the Parshall Flume was also started.
The volume of rain registered in February was above the historical average and this had a negative impact on the deadlines for the execution of the structures on the Floresta Farm grounds and the release of sectors to receive sediments.
This month, some 19,865.09m³ of the sediment deposited in the stretch between the Risoleta Neves HPP and the A Barrier was dredged in the resumption of services. The dredging services of Phase 1, sector 1, were resumed and the HDPE pipeline crossing the Peixe River was completed.
In Candonga (MG), the focus continues on the services for dredging and recovery of the reservoir banks and the construction of structures for the treatment of dredged effluents within the Floresta Farm.
As a result of significant rainfall in December, which damaged the left and right shoulder of barrier C, the deadline for finalizing the construction of the barrier was delayed until March 2018. The shoulders are being repaired and the rework on the right shoulder has been completed.
The decommissioning of Sector 8, which includes the compaction and encapsulation of the soil that remains below the reservoir flooding level, is underway by bioengineering services.
Also, in January, as per recommendation of AECOM (MPE audit), embankment services to the intermediate and main dikes were paralyzed to verify the foundations of the structures. New authorization for resumption of services was granted on January 29.
The Renova Foundation is still awaiting the authorization of Semad and the National Water Agency (ANA) to carry out the manipulation of polymer within the Permanent Preservation Area.
The absence of a disposal area meant that the dredging work was paralyzed throughout the month of December. The accumulated dredging between July and December 2017 (261,408 m³) is below planned (315,000 m³). The services to treat the slopes were started in order to protect the slopes of the banks of the reservoir and of the dikes of the Floresta Farm, in preparation of the filling the reservoir.
About 34,561 thousand m3 of sediment deposited in the stretch between the Hydroelectric Power Plant Risoleta Neves and Barrier A was dredged.
In Candonga (MG), the focus continues on the services for dredging and recovery of the reservoir banks and the construction of structures for the treatment of effluents at the Floresta Farm.
The installation of the metal structure for the construction of Barrier C was completed, which will be part of the tailings retention system located inside the HPP reservoir. This completes another stage of the tailings management program, avoiding sediment carriage from the Fundao dam to the Doce River mouth.
On November 22, the State Department of Environment and Sustainable Development (Semad) signed a Term of Conduct Adjustment (TAC) authorizing the construction of Basin 01 for the Floresta Farm within the Permanent Preservation Area (APP).
Ongoing is the decommissioning of Sector 8, which includes soil compaction and encapsulation, which will be below the reservoir flooding quota.
In November, the services of planting on slopes were started, for the protection of the slopes of the banks of the reservoir and the dikes of the Floresta Farm.
Renova is still awaiting authorization from Semad and the National Water Agency (ANA) for the handling of polymer within the Permanent Preservation Area, a document necessary for the resumption of activities for filling ecobags.
The plans for filling the reservoir of the Risoleta Neves HPP and maintenance dredging for Phase 2 were submitted. Among the planned activities, 27,134 cubic meters of sediment deposited in the stretch between the Risoleta Neves Hydroelectric Plant and Barrier A were dredged.
In Candonga, the focus continues on the works for dredging and recovery of the banks of the reservoir. The installation of the metal structure for the construction of Barrier C was completed, which will be part of the tailings retention system located inside the reservoir. The barrier will reduce de tailings that flow from the Fundao dam to the mouth of the Doce river.
In the reservoir of the Plant, dredger B50 started its operations, equipment that will dredge sediments to the storage structures on the Floresta Farm, a site acquired by the Renova Foundation. Another relevant initiative was the beginning of the decommissioning of Sector 8, which includes soil compaction and encapsulation, which will be below the reservoir flooding quota.
At the Floresta Farm, the surface drainage works of the levees were started. The activities of filling the ecobags in Sector 4 are suspended, pending the authorization of the State Department of Environment and Sustainable Development (SEMAD) and the National Water Agency (ANA) for the handling of polymer within the Permanent Preservation Area.
SEMAD has not yet issued the Term of Adjustment of Conduct (TAC) of Basin 01 of the Floresta Farm. The document is required for the completion of the dredging deadline in July 2018, as determined by the CIF, in order to start the definitive filling of the Candonga reservoir.
On October 16, repair works in the region around the Plant were paralyzed due to demonstrations by residents of the Rio Doce and Santa Cruz communities, who claim their indemnity payments are delayed. The issue is being analyzed by bodies such as local governments and the Prosecution Service.
About 52,3 thousand m3 of sediment deposited in the stretch between the Hydroelectric Power Plant Risoleta Neves and Barrier A was dredged.
In Candonga, the recovery of the banks of the reservoir began and the first metal stake of Barrier C, the third structure under construction to contain the tailings between the Fundao and the Plant, was installed.
After authorization to resume activities and deactivation of the soccer field of the Floresta Farm, the company responsible for earthworks was mobilized and the earthmoving services at the new soccer field site, in the district of Santana do Deserto (MG), were completed.
The first welding was carried out on the pipelines that will transport the dredged material from the Candonga reservoir to the Floresta Farm.
Some 76,300 cubic meters of sediment deposited in the stretch between the Risoleta Neves Hydroelectric Plant and the Dam A were dredged.
As a solution for treating dredged tailings, a descriptive memo was filed with the Secretariat for Environment and Development (Semad). It proposes the use of reagents (coagulants and polymers) in the bags that receive the material. The pilot plan for the testing of these polymers was also filed with Semad to start dredging in the temporary tailings storage area on the banks of the reservoir.
The Municipal Government of Rio Doce (MG) issued a "precarious authorization" allowing the resumption of activities on the Floresta Farm. With this, the vegetation suppression services were restarted and the request for purchase of gravel and rock for the structures of the Farm was completed.
The local authorities of Rio Doce authorized the initiation of the removal of the football field from the Floresta Farm and the construction of another field in a to-be-defined place.
The activities of earthmoving and deployment of the polyethylene pipe line (HDPE), which will transport the dredged material from the plant's reservoir to the Floresta Farm, were started.
For the construction of Dam C, there was the delivery of the first load of metal tubes and earthworks were started. For Dam A, the concreting of the cables of the metal stakes was completed.
Beginning of the negotiation process with the Municipal Government of Rio Doce, in Minas Gerais, for the issuance of a "precarious authorization" for the resumption of services in Fazenda Floresta until the "Permit for Construction Works" is issued.
The Municipal Council for Artistic and Cultural Heritage (COMPAC) visited the Fazenda Floresta for the withdrawal of the soccer field from the historical heritage process. The area of the new soccer field is in expropriation by the Municipal Government of Rio Doce.
Delivery of the report of reagent use tests at the State Department of Environment and Sustainable Development (SEMAD), which marks the starting point for the use of polymers in ECOBAGS and in the treatment structures of tributaries of the Fazenda Floresta farm.
Start of earthworks services of dam C and opening of two new tailings disposal sites within the wetland of the reservoir of the Risoleta Neves Hydroelectric Plant, sectors 03 and 06.
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