At the end of 2023 and the beginning of 2024, we carried out an extensive renovation of Clarifier No. 2 in Building A of the Ülemiste Water Treatment Plant. The construction work included demolition, renovation of barriers, sealing of water leaks, pouring of the tank’s concrete floor, and repairing the concrete floor, walls, columns, and beams of the water tank. The barrier and load-bearing structures of the water tank were covered with a Sika waterproofing system suitable for drinking water.