Transportation of wastewater to the collector of Stara Zagora’s waste water treatment plant
The main collector consists of two paralleling DN 2000 pipelines, a road drainage, 18 shafts for inspection and a overflow, not to mention auxiliary facilities such as road links, intersections with the railway, etc. The main technical challenge, however, was the limited width of the pipe trench and the small clearance (approx. 60 cm) between the two lines. Already in the design phase had HOBAS experts proposed a technical solution for pipe laying and backfilling, which was gladly accepted and laid down in the design. Thanks to the regular visits by HOBAS site advisors throughout the construction works, a risk of pipe buoyancy in the ferroconcrete casing running under railway lines was recognized and averted with an appropriate technical solution. HOBAS also shared its valuable international expertise when it came to testing the line after its successful installation. The pipeline was officially inaugurated on October 24th 2008 in the presence of Bulgarian ministers, the Mayor of Stara Zagora, the District Governor and lots of guests and friends.