Conducting an integrated environmental impact assessment and feasibility study for the safe management and remediation of the uranium legacy complex of Mailuu-Suu

The overall objective is to conduct an integrated environmental impact assessment (EIA) and feasibility study (FS) of the possible remediation and related management activities for the Mailuu-Suu uranium production legacy site.

The project tasks will comprise among other things:

• Analysis of the national legislative and regulatory framework;
• comprehensive and meticulous assessments of the current status of the site and radiological surveys of the nearby inhabited urbane areas, including physical, demographical, geological, hydrological, hydro-geological, radiological characterisation;
• comprehensive characterisation of the legacy waste; present and long term impact assessment (radiological and non-radiological);
• risk assessments; feasibility study with proposed remediation plans, including mitigation measures to minimise the risks of the remediation activities;
• evaluation of the environmental, social and economic impacts;
• development of remediation plans including all necessary documents (design, drawings, budget, time schedule, etc.) to obtain approvals and tender the remediation works e.g. development of environmental monitoring and maintenance plan, assessment of the available services, tools, skills and training of personnel;
• public consultation and awareness;
• identification of needs for implementation of environmental and radiological assessment recommendations;
• detailed analysis and design specifications for mobile and fixed equipment for risk monitoring systems at legacy sites in Kyrgyzstan (the supply is not part of this service contract).

The objective of this project was to conduct an environmental impact assessment and feasibility study, for the safe management and remediation activities for the Mailuu-Suu Uranium legacy site in Kyrgyzstan. These studies will be the basis for subsequent decision making regarding remediation of the site.

The complex Mailuu Suu legacy sites can be subdivided into the following objects:

• 39 waste rock dumps of various sizes;
• 16 tailings ponds (TP);
• 6 shafts;
• 49 adits;
• 2 ore processing plants; and
• 83 mine buildings/ruins.

In order to achieve the set objectives and purpose, the following project activities were carried out:

• The identification of policy and institutional needs for implementing the recommendations issued within the scope of the project (Tasks 1 to 9)
• Design, Technical Specifications and supervision of installation of mobile and fixed equipment for risk assessments at legacy sites in the Kyrgyz Republic (Task 2)
• The involvement of all relevant stakeholders such as local authorities, the population affected by the uranium legacy sites and other organisations (Task 9)
• A detailed description and characterisation of the current legal and regulatory framework (Task 3.1) and of the current geological, physical, chemical and radiological status of both sites (Task 3.2)
• A risk assessment of the current situation (Task 4)
• A thorough integrated analysis of alternative remediation activities of both sites, including a cost estimation and a safety analysis (Tasks 5 and 6)
• The determination of significant social, safety and environmental a) positive and negative impacts, b) direct and indirect impacts, and c) immediate, short and long-term impacts of the proposed remediation activities including management plan to mitigate the negative impacts of the remediation works (Task 8)
• Monitoring plan (Task 7).

The project started on 19 October 2017 and was successfully finished on 31 August 2020. The Final Meeting was held on 12 August 2020.

The technical part of the project started in November 2017 with the first phase of Task 2, i.e., the preparation of Technical Specifications for installation of equipment for risk assessment of legacy sites (landslide monitoring) and Task 3.1, the update of analysis of the legal and regulatory framework in Kyrgyzstan. New or amended laws, regulations and guidelines were reviewed with a view to their impact on project implementation and were compared with accepted international regulations and standards. Gaps and discrepancies with respect to international best practice were also identified but were relatively minor.

The next project phase (Tasks 3.2 and 4) included the assessment of the current status of the Mailuu Suu legacy sites by using engineering surveys, sampling and measurements, field inspections, review of existing documents, etc., with the aim of obtaining a complete, sound description of the status of the sites and the risks resulting from the existing situation.

The data review and investigations revealed a significant degradation of the local socio-economic and natural conditions as a consequence of previous uranium mining activities and remaining legacies. Effective doses arising from the legacy objects were found to be below the reference levels of 1 mSv/year for the total effective dose, and 0.1 mSv/year for drinking water, respectively. Outdoor radon concentrations are in the order of 30 Bq/m³. There are several accessible water sources exceeding the Kyrgyz drinking water limit of 30 μg/l for uranium.

The following objects have a high or medium risk, which has resulted in proposed remediation actions:

• Five tailing ponds show high risk for erosion, potential flooding or surface water inflow and, consequently, may lead to transboundary pollution
• Three tailing ponds have a medium risk because of erosion or steep gabion dam.
• Four shafts show a high risk, two shafts show a medium risk.
• Nine adits have a high risk, nine adits show a medium risk
• Several buildings and abandoned infrastructure objects have a high or medium risk.

The following remediation measures are proposed:

• In the Ailampasay valley, a tributary valley to MS valley, the relocation of TP2 and TP13, for disposal on TP1 and TP4 and the armouring of the Ailampasay riverbed are proposed.
• For TP16 in the Ashwazsay valley, the installation of a dam buttress, a new cover and new water diversion are proposed.
• In the MS valley, the preferred remediation option for TP5 and TP7 is a dam buttressing on a length of 800 m. The buttress should be covered with large armour stones for erosion protection.
• Relocation of TP 8 and TP 18 to a new constructed disposal cell at TP 15 area is proposed.
• For all tailings facilities, a standard cover is proposed to prevent access to tailings in the long-term. New diversion channels should be built on the new cover. The relevant sites are TP6-east, TP9, TP10, TP11, TP14 and TP19. For the small TP19, buttressing of the existent gabion dam is proposed.
• Demolition of all risky, dilapidated mine buildings is proposed. Finally, the areas should be covered with clean soil.
• The local population needs to be informed about the contaminated water sources. It is proposed to erect warning signs at 21 accessible places.
• Concrete slabs for shaft closure are proposed.
• Brick walls and crushed rock for the closure of adits are proposed.

The general remediation strategy of Task 5 and the subsequent feasibility studies developed under Task 6 have been agreed with, and endorsed by, the Beneficiary.

The engineering design documents comprise the following:

• A detailed design, including “Explanatory Notes”, of the construction works with detailed descriptions of all planned activities,
• The “Technical Specifications” as a basis for tender documents of the remediation works,
• A detailed Bill of Quantities including cost estimates.

The total construction costs for the Mailuu Suu site are approximately 20.9 million €.

Monitoring programs for the remediation works and the post-remediation period have been developed under Task 7. Additional needs for the existing monitoring capabilities and for stakeholder involvement have been identified.

Environmental Impact Assessment (EIA) studies for remediation works were prepared in compliance with Kyrgyz and international standards and agreed with the Kyrgyz authorities under Task 8. The overwhelming majority of impacts has negligible or minor significance, if the proposed mitigation measures are implemented. Impacts due to noise and dust are restricted to the project implementation period. Impacts on habitats are reversible and, hence, moderate. This means that habitats will recover as soon as the remediation works are completed. No unacceptable environmental impacts of the remediation works are expected. Effective doses to members of the public will remain well below 1 mSv/a at all sites.

Appropriate monitoring activities and mitigation measures commensurate with the level of risk and environmental impact during and after remediation have been developed.
Key elements of the post-remedial monitoring activities for the remediated sites are:

• Control of the stability of closure measures at shafts and adits
• Control of the integrity and functionality of technical structures (water diversion channels, water pipes, cover on contaminated areas), and maintenance measures as necessary
• Control of warning signs and implementation of a public risk awareness programme related to the use of water that is unsafe for human consumption
• Control of the quality of discharge water as a matter of precaution.

Public consultation and participation activities, involvement of relevant governmental agencies and local stakeholders have been continuously implemented during the project. Each individual project task was performed in close collaboration and agreement with the Beneficiary and other relevant Kyrgyz organisations. In particular, a successful stakeholder involvement and information program was implemented under Task 9 in close collaboration with the Beneficiary and the local Aarhus Centres. Formal regulatory requirements were followed in the preparation and carrying out of the stakeholder consultation meetings. No objections to the proposed remediation program (Feasibility Study) and the findings of the EIA were raised by the local stakeholders.

All deliverables (technical reports) have been endorsed by the Kyrgyz project counterpart.

The project deliverables were also positively assessed in a peer review by a team of experts set-up by IAEA. The peer review team also gave some recommendations to be taken into account in the final planning of the remediation activities.

All objectives of the Project have been achieved within the project duration of 34 months as per the contract and its amendments.

During the project implementation phase, significant problems were encountered:

The first significant problem was the very long time, required for the authorization and custom clearance for the import of technical devices for the monitoring system (Task 2). The import was under the responsibility of the supplier but influenced the project.

The second significant problem was the identification of a common basis by Beneficiary and Contractor for one of the technical solutions for the remediation of the tailings ponds. It took several months of discussions and a prolongation of the project time and finally an additional technical meeting in Brussels to find a solution.

In the final phase of the project the Covid 19 pandemic prevented travelling and made it impossible to organise a public hearing in Mailuu Suu to present and discuss the Feasibility Study and Environmental Impact Assessment, and to hold the final workshop in Bishkek.

Based on a regular presence of the Contractor’s staff in Kyrgyzstan and close co-operation with the Beneficiary, local population, regulatory authorities and Kyrgyz sub-contractors, the following conclusions can be drawn:

• Close communication with all groups of stakeholders in their local language is key to success
• Working conditions in the country need to be analysed and respected/considered carefully, when managing the project
• Flexibility in finding alternatives and solutions is required, when the primary working option is blocked; wasting time with insisting on the primary approach is unlikely to be successful
• Sufficient financial resources, based cost estimates of the post-remediation activities (monitoring, surveillance, maintenance, corrective action) should be available under the state budget.