Analysis of the confined spaces atmospheres in a wastewater drainage network

Abstract

There is an underground technical infrastructure for the disposal of wastewater in most of urban areas, which is periodically targeted for maintenance and rehabilitation by specialized workers, or even used more specifically by authorities or emergency forces. Each entry point can be considered a separate confined space, where there are hazardous atmospheres to the physical integrity of the workers. To understand the hazards to which all subjects are exposed, a systematic and exhaustive analysis was carried out in the interior atmosphere of the manholes in the wastewater drainage network, in the entire eastern zone of the city of Beja, the gases produced and at those facilities. The collection of the data was performed when the network was its normal state of exploration, had minimum flows. The flow rates were classified as minimum, after analyzing the readings of recording of the flow meters installed in the zones of measurement and control of the water distribution network, in two very distinct periods.