The building joint-venture Čistá Plzeň will be constructing sewerage and water distribution infrastructure on an extensive territory for three years. The joint-venture consists of HOCHTIEF VSB as the leading member (34 %), METROSTAV (25 %), STAVBY SILNIC A ŽELEZNIC (23 %), TCHAS (10 %) and STRABAG (8 %). The project is the biggest one in the Pilsen region in the past few years.
The project in the total value of 1.7 billion CZK has been supported by the Cohesion Fund of the European Union with the contribution of ca. 1.2 billion CZK. 64 million CZK will be provided by the State Environmental Fund (SFŽP). The rest will be funded from a loan to the City of Pilsen from the European Investment Bank .
The scheduled completion date is 31 October 2008. A precondition set by the city and the European Union is that implementation of all the parts of the project should start at the same time. The biggest constructions in the complex include backbone water mains to the municipal parts of Lobzy and Vinice. The project also includes sewer systems for Valcha, Křimice, Radčice and Lochotín. New retention tanks Gera and Bolevec will be developed to retain storm rainfall and to prevent flooding of the sewerage system.
The biggest modern time municipal investment will treat waste water before it is discharged into the Berounka River, it will deal with the deficit in sewerage and improve drinking water supplies for Pilsen, particularly at its outskirts.
The water supply system Lobzy will consist of force main of drinking water led from the water reservoir Homolka through the city districts Slovany and Lobzy to the location of the newly proposed water reservoir Lobzy. The reservoir Lobzy is designed for the collection of drinking water of total volume up to 2 x 10000 m3. The work will include new more powerful pumps including their standby. This water reservoir will eliminate the problems of drinking water supply in the city districts Lobzy and Doubravka, in particular along the Rokycanská avenue, where insufficient pressure in the network causes the problems. The water supply system will also include connection mains. Total length of piping will be approx. 7 kilometres.
The main structure of the Vinice water supply system will be a reservoir of total drinking water accumulation volume 2 x 6000 m3. The system will also include connection mains as well as connection to two force mains to the water reservoir Sylván. The water reservoir Vinice facilitates the drinking water supply to the city district Roudná, part of Lochotín, Vinice, and the city centre. At the same time in near future it will be possible to put out of operation the old and troublesome force main from the water reservoir Bory to water reservoir Sylván.
The Valcha sewer system will have an overall length of approx. 9 km, of which 2 km will be a head sewerage system made of ductile cast iron pipes. The system will be connected to the existing main sewer Litice. Sewage will be pumped by 5 pumping stations.
The sewer system in Křimice, Radčice and Lochotín will have an overall length of approx. 14 km, of which almost 6 km will be a head sewerage system. The system will enable a good quality living in the periphery of the city of Pilsen, and, as it will be connected to the existing sewer system of the city, the sewage will be treated in the city waste water treatment plant before it is discharged into the Berounka River.
The retention tanks Gera and Bolevec have been designed as underground reinforced concrete monolithic structure with useful retention volumes of 2350 m3 and 3100 m3 respectively. The retention tanks will reduce the flow rate of the sewage water in the sewer, in particular during heavy rain, and thus reduce the risk of sewer damage and enable subsequent cleaning of the sewage water temporarily caught in the retention tank before it is discharged into the river. The works include a water pipe for reservoir cleaning, electric connection, and a road connecting the structure with the city road network.