Germany – Sewer construction work – Sanierung der Abwassergrundleitungen im Außengelände der GS Albert Schweitzer. Sanitärtechnik nach VOB DIN 18381

At the Albert Schweitzer Elementary School, all main drainage pipes for wastewater, rainwater, and combined sewer overflow in the school grounds are being renovated. The construction project at the Albert Schweitzer Elementary School includes the following work: - Construction of a new wastewater main line with approximately 1100 m of sewer pipe (DN 100-300) including the associated excavation work, - Construction of 18 inspection and access chambers, - Construction of 25 catch basins (yard drains), - Construction of the new main combined sewer overflow pipe to the existing wastewater collection basin, which, via a pumping station, feeds the wastewater into the sewer system. The construction project is divided into four phases with the following work: Phase 1 - Execution from July 1st to August 25th, 2025 - Construction of a wastewater main line (combined sewer overflow) with approximately 150 m of DN 200-300 pipe, - the associated excavation work must be carried out primarily by hand. The main wastewater line runs under a break area canopy (see images) which is partially permanently attached to the building. The excavation work is being carried out at depths of 1.65–3.43 m using shoring and manual excavation. This includes: dismantling and disposal of the old wastewater line (vitrified clay); completion of the work within the six-week school holidays; approximately 35 connections (sewage/rainwater/mineral water) along this section, which must first be temporarily connected to the new main line. These connections will later be made to the newly constructed main lines of the respective sections. The main combined sewer line will be laid with a gradient of 1% (1 cm/m), which is necessary to maintain the existing elevations (wastewater collection basin). Section 2 - Execution August-November 2025 - Installation of all main drainage pipes to the main groundwater pipe (lines RW 1-2, 8-14) and to the drainage points; - Installation of a shut-off valve for each...