Vodokanal of St.Petersburg demonstrated water treatment process to journalists


On April 16th, specialists of SUE “Vodokanal of St.Petersburg” invited mass media representatives to the K-6 Unit (water treatment facilities complex) at the Southern Water Treatment Plant. On April 22, the K-6 Unit celebrates its 10th commissioning anniversary.

The facility was put into operation in 2011 and has become an example of the most up-to-date approach to water treatment. Every year 35-40 delegations from water utilities in Russia, the CIS and foreign countries visit the facility to exchange experience.

The K-6 Unit includes more than 650 items of process equipment, and its capacity reaches 350 thousand cubic meters of water per day. During the press tour Irina Bobrova, Director of the Southern Water Treatment Plant, described its operational principles and technologies applied. Media representatives were able to eyewitness a full cycle of St.Petersburg drinking water treatment and disinfection.

The main source of water for St. Petersburg is the Neva River, which is characterized by seasonal fluctuations in water quality. Process solutions implemented at the K-6 Unit ensure high quality of drinking water treatment regardless of the source's condition and reduce the negative impact on the environment.

An important benefit of the facility is absence of untreated process water discharge into water bodies. The backwash water from filters is treated and supplied to the plant head. Thus, the K-6 Unit reaches minimum figures of water used for own needs - 3–6 times lower compared to other water treatment facilities in St. Petersburg.

The settling tanks sediment is dewatered in centrifuges and transported for disposal. The K-6 Unit treatment process layout has proved its performance and is recommended as one of the best available technologies for the Neva River source water treatment. The K-6 Unit supplied drinking water quality meets the most stringent requirements and standards.

There is a two-stage water treatment system in this plant. The first stage includes coagulation, flocculation and settling in a lamellar clarifier. The second stage is filtration through two-media rapid gravity filters (sand and granular activated carbon).

SUE “Vodokanal of St.Petersburg” monitors water quality from the moment of water intake from the water supply source to a house connection water metering unit.

In 2020, more than 24,561 water samples were taken and analyzed as part of industrial water quality control. The results showed that drinking water in St.Petersburg is chemically harmless and safe in epidemiological and radiation terms.

Water quality control is carried out on a daily basis by Vodokanal and independent organizations - FBUZ “Center for Hygiene and Epidemiology of the City of St.Petersburg” and the St.Petersburg Department of Rospotrebnadzor.

The water quality control program comprises 409 sampling points, including 354 points along the distribution network, where water quality is monitored for more than 94 indicators: generalized, organoleptic, chemical (organic and inorganic), microbiological, parasitological (lamblia cysts), virological (presence of hepatitis A virus antigen, rotavirus antigens), hydrobiological (phyto- and zooplankton), radiation safety indicators.


Vodokanal of St.Petersburg is one of the largest water utilities in Russia. The Company provides drinking water and sanitation services to more than 5.3 million residents of the city and tens of thousands of companies.

Today SUE “Vodokanal of St.Petersburg” operates:

- 9 water treatment plants (the largest are Southern WTP, Northern WTP, Main WTP);

- 22 wastewater treatment plants (the largest are Central WWTP, Northern WWTP, South-West WWTP);

- 189 booster pumping stations;

- 241 sewage pumping station;

- 7.6 thousand km of water supply networks;

- 9.4 thousand km of sewerage networks;

- 279 km of tunnel collectors;

- 3 sludge incineration plants;

- 2 sodium hypochlorite production plants;

- 11 permanent snow-melting stations (PSS) and 7 permanent technically-equipped snow collection points (PTSCP).