The town of Sliven is situated in Southeastern Bulgaria, at about 300 kilometers east of Sofia. It is the administrative center of Sliven region and has a population of slightly more than 110,000 people.
Purpose: Urban wastewater treatment plant
Location: Sliven town, Bulgaria
Client: Bulgarian Ministry of Water and Environment
Services provided: Construction supervision
In the period from March 2009 to July 2012, a reconstruction and upgrading of the urban wastewater treatment plant (UWWTP) was carried out, financed with funds provided jointly by the European Union and Republic of Bulgaria, part of the ISPA measure for implementation of "Integrated project for improvement of the water cycle of the town of Sliven". The construction contract was signed based on the Conditions of Contract, according to FIDIC, for Plant and Design-Build for Electrical and Mechanical Works and for Building and Engineering Works Designed by the Contractor (Yellow Book), in compliance with Bulgarian laws and regulations.
In October 2008, following a public-procurement procedure, the Bulgarian Ministry of Water and Environment awarded an assignment to the Consortium named “Sweco International and Energoproekt-Hydropower”, with leading partner Energoproekt-Hydropower Ltd (Bulgaria), whose successor is Sweco Energoproekt Jsc, and partner Sweco International AB (Sweden), for provision of the following consultancy services in connection with the implementation of the reconstruction of Sliven UWWTP:
Conformity assessment of the investment project’s design and implementation of construction supervision according to Bulgarian Law on Spatial Planning;
Execution of the functions of Engineer, according to the conditions of contract of FIDIC Yellow Book.
In the design for reconstruction of Sliven UWWTP is foreseen the plant to serve a population of 170.000 PE in year 2025. The reconstruction and upgrading of the waste-water treatment plant included the following components:
Reconstruction of the mechanical treatment level, incl.: construction of new intake shaft, new building for coarse and fine screens, new sand trap, reconstruction of the distribution device and of the primary radial settling tanks;
Construction of new biological treatment level: new aeration tank with nitrogen and phosphorus removal, new distribution device and new secondary radial settling tanks;
Construction of new gas facilities, incl.: new methane tanks with a building to them, new gasholder, and of co-generators for the methane utilization;
Development of a system for automatic control of processes (SCADA);
Construction of new administrative building.
The share of Sweco Energoproekt Jsc in the implementation of the assigned services is 95%, as they were started in March 2009 and completed in July 2012, including the 12-month defect notification period, according to conditions of contract of FIDIC Yellow Book.
With the implementation of the assigned construction supervision services, Sweco Energoproekt Jsc contributed to the successful implementation of the overall project: "Integrated project for improvement of the water cycle of the town of Sliven ", in particular to the part of this project related with the reconstruction and upgrading of the urban wastewater treatment plant (UWWTP), by assisting the Ministry of environment and water in the pursuit of quality supervision and control services.