Sofiyska Voda will invest almost 14 M BGN in 2018 in the construction of sewer network

“The Ninjas” are the specialized team that helps avoid serious failures along the boulevards with heavy traffic in the capital

Sofiyska Voda will invest almost 14 M BGN for wastewater drainage and construction and rehabilitation of the sewer network in accordance with its investment program. This is almost 2 M BGN more compared to the money invested for that purpose in 2017 and 4 M BGN more than the money spent in 2016.


 “The maintenance of the sewer network is a very important aspect of the activity of Sofiyska Voda despite the fact that people cannot see it, as it is below the ground. In 2018 we will invest almost 14 M BGN, construct new sewer network and continue maintaining the sewer system in a very good operating order”, said Vasil Trenev, Executive Director of Sofiyska Voda.

It is planned the construction of a new sewer network and the rehabilitation of the existing one. Parts of the sewers in the capital were constructed at the end of the 19th century. Sofiyska Voda maintains almost 1,700 km of sewer network and another 4,000 km of water network. 

One of the most important infrastructural projects for the year is the construction of a sewer network in Simeonovo and Orlandovtsi residential quarters and the already started reconstruction of a sewer along Graf Ignatiev St. and on Slaveykov Sq. Upgrades of the digesters and the cogeneration installation in the wastewater treatment plant in Kubratovo are envisaged to the amount of more than 4 M BGN. A lot of money is envisaged also for the reconstruction of the sewer network and the water network in Krasno Selo, Benkovski and other residential quarters in Sofia. 
The construction of the sewer network takes place with the active support of the Municipality of Sofia. Under the Amendment Agreement with it additional investments amounting to more than 4,400,000 were negotiated.

On a daily basis the teams of Sofiyska Voda make regular maintenance of the sewer network and the schedule is prepared on the basis of the criticality of the facilities. Regular inspections are carried out using complex practices recognized worldwide such as robotic camera inspections, manual camera surveys and building of a computer-based hydraulic model of the sewer network etc. In the low areas, where the network gradients are small and debris accumulate, the frequency of the preventative works is increased in order to avoid the risk of floods. 

“The organization of our work is based mainly on the preventive activities in order to have the sewerage system cleaned and ready for the bad weather conditions and torrential rains. In order to find problematic sections in the pipes we also set up a dedicated team for their physical survey”, commented Stanislav Stanev, Operations and Maintenance Director of Sofiyska Voda.

In fact, that is the only similar team in Bulgaria which is walking inside the sewers and it is no accident that it has been called “The Ninjas”. The team surveying big sewers makes real-time inspections and CCTV recordings, as in this way it prevents future serious collapses, including of main boulevards with intense traffic. The professionals have passed through specialized training and are equipped with special protective clothing, as inside the sewers they are working in an explosive environment and there is a risk of the existence of hazardous gases. While moving in the sewers there is one more peculiarity – if a person normally moves at 3-5 km/h, in the sewers that happens much slower, at a speed of up to 500 m/h.

Sewers are also cleaned using specialized equipment. The newest acquisition of the team is a MAN sewer-cleaning machine worth 976,000 BGN, VAT excluded. Sofiyska Voda has equipment and machinery for cleaning the system, as besides the 11 sewer-cleaning machines there are excavators, cameras, dump trucks etc. at total value nearly 6 M BGN.