a worker installs a sewer manhole on a septic tank made of concrete rings. construction of sewerage networks for country houses

access assembly biological builder cesspool cleaning communications concrete construction country cover disposal drainage equipment fecal fix ground hatch hole houses hygiene industry installation installs made maintenance male man manhole networks outdoor pave pipeline plumbing pumping purification repairman reservoir rings round sanitary sanitation septic sewage sewer sewerage storage structure system tank toilet treatment trench underground utility waste water work worker