Reconstruction of the biological wastewater treatment plant of the Buinsk Water Treatment Plant was carried out as prescribed by environmentalists. This year, as a result of joint control measures performed by specialists from the Zavolzhskiy Territorial Administration of the Ministry of Ecology and Natural Resources of the Republic of Tatarstan and the Buinsk city prosecutor's office, violations of the operation of wastewater treatment plants at the plant were revealed: ecologists found outflows of maximum permissible concentrations of pollutants in wastewater.