Serial mobile block-modular installations PlanaOS-B-50 are designed for operation at temporary camps for builders of oil and gas pipelines and at oil and gas industry facilities. The versatility of the installations is achieved largely due to the MBBR biological treatment technology using bio-loading — a complex of mobile activated sludge carriers, and a large margin of technological capacity. Built-in effluent heating and post-treatment section ensure the achievement of standard indicators with significant fluctuations in loads at the inlet to the WWTP. The block design allows the station to be dismantled, transported and installed at a new construction site.