GSP-Project Ltd experts conducted diagnostics of high-speed turbocompressors, operated since 2012 year. During the operation period, under the maintenance, inlet filter cartridge and inlet pocket filters were replaced, the PT100 temperature sensor and SPI board were replaced after 5 years of operating. The equipment operates stably, does not cause complaints and provides all the process needs of the aeration process at the plant. Pushkin WWTP (ex-name Tsarskoye Selo WWTP) built by order of the Emperor Nikolas II at the 1902-1905 years, when a sewage system was installed in the city, which initially served palaces and barracks. This WWTP is the first biological wastewater treatment in Russia.