The project "Remediation works of historically polluted areas "Inčukalns sulfuric acide gudrona ponds" (hereinafter – the Project) envisages restoration works of the ponds of Southern and Northern sulphuric acid in the territory of Inčukalns county 30-35 km east of Riga. Wastes containing lubricating oils and sulphate acids, which are considered to be sulphuric acid, were dumped into ponds by the refinery and lubricating oil plant in Riga, which no longer exists. Other wastes resulting from the manufacture of medical and perfumery oils were also dumped into ponds. The composition of the waste is complex because it has resulted from uninterrupted physical and chemical processes.The landfill was closed in 1986, since then pollution from the gut ponds by infiltration has reached groundwater and arthetic waters at 70-90 m depth. Polluted artesian waters at a speed of 25-35 m/year move north towards the River Gauja. Areas of contaminated groundwater: For the Northern pond – 148 ha, for the Southern pond – 139 ha. The financial and physical implementation of the project is divided in two stages with a total indicative cost of 57.86 million euros. Phase I of the project includes works up to 31 December 2015, while Phase II of the Project includes the remaining works for which a new recovery contract will be concluded and which will be implemented within the 2014-2020 EU fund programming period starting from 1 January 2016.In the project under the 2007-2013 planning period of the EU funds within the 2007-2013 planning period of the project, the completion of the project phase before 31 December 2015 the Phase I activities – partial recovery of the Southern pond, supervision and engineering services, the Southern Podm management within the 2007-2013 planning period, the completion of the project phase II within the sanitation period of the project, the partial recovery of the Southern pond, supervision and engineering services, the Southern Pond management, the planning phase of the project within the planning phase of the project, the completion of Phase I of the project – partial recovery of the Southern pond, supervision of the recovery work and engineering services, the Southern Pond of the 2007-2013 Legal Planning phase until 31 December 2015, the project-construction planning phase II within the sanitation period of the project – partial recovery of the Southern pond, supervision and engineering services of the Southern Pond, the Project Provisional Planning Phase II, the Conclusion of the Project within the Planning Phase II, and the completion of the Project Planning Partial Recovery, Monitoring of Recovery and Engineering Services, Southern Pond Management – Preliminary Operational Phase II of the Project within the Planning Phase II, while the Project Phase II – Preliminary Counning of the Project, Project Phase II – Preliminary Operational Phase II – Completion of Sanitary Phase II – The supervision of the recovery work and engineering services, Southern Pond Management, Provisional Operational Phase II of the Project, while the Project’s Phase I activities – Partial recovery of the Southern Pond, supervision and engineering services, Southern Podian Planning Phase II – Completion of the operational phase of the EU within the 2015-Year period of the project, until 31 December 2015, phase II of the project, phase II of the project, and phase II of the project, which will be implemented as part of the 2014-2020 EU fund programming period starting from 1 January 2016. The activities carried out under the Project Phase I and the activities planned under the Project Phase II are listed in EC Decision No C(2016) 3382 of 7 June 2016 on the amendments to Commission Decision C(2010) 8465 of 20 December 2010 on the Major Project’s Majorly Polluted Sites ‘Inčukalns Source Ponds’ Decision No.C(2016) 3382 on the project’s exemplary exemplary costs.Under the exemplary work of the European Regional Development Fund and the Cohesion Fund’s structural assistance action programme ‘Infrastructure and Services’ under the Convergence objective of the CCI, the Protection of the Effiliation of the Programme, the Work of the Priority of the Programme of the European Regional Development Fund and of the Cohesion Fund are available under the Convergence objective of the CCI, the Protection of the Effective Plan, the Commission’s Work for the Priority of the Programme. The increase is also confirmed by the ongoing procurements for completion of renovation works and engineering supervision. JASPERS experts also pointed out the risk of a possible increase in the costs of completing the rehabilitation works in their final report on proposed amendments to the Project in 2015 (see Annex VI amendments to the project approved by EC Decision).•A re-indexation of the costs of Phase II of the Project was carried out by the end of 2023.