Sludge gathers in septic tanks and containers gradually. The sludge needs to be taken away at regular time intervals so as to keep a smooth running operation. Sludge removal can be a dangerous undertaking if performed manually. For this reason septic tank and container sludge removal is undertaken remotely wherever doable, or with minimum man-entry in limited areas.
A variety of tools have been engineered for the oil and gas business, as well as the chemical industry and others for sludge removal. Vacuum exchange devices can pump sludge safely from its source to a transport or storage source. Apart from an individual maintaining the program remotely, no one needs to be near or even very close to the tank or vessel having its sludge taken away. Of course, often it isn't possible to remove sludge, mud or scale from a tank or vessel by a remotely controlled system and no man-entry requirement. Often man-entry becomes essential, and often it is in a limited and cumbersome space, which makes the operation possibly risky.
For this reason, there are extremely skilled agents in the field who follow tested procedures that are known to be reliable and useful. The task gets completed with the lowest possible threat to those included, and the sludge removal and clean-up is maintained at an acceptably high and successful level. An Attendant stays close to the position of man-entry. He always watches the situation in the enclosed space. He keeps in consistent communications with the entrants working inside to make certain that all the approved best working practices are preserved and followed to ensure the safest possible level of working conditions.
It is also essential to maintain a constant monitor on gas build up within the limited space where the entrants are doing the job. For this reason gas observation equipment is used and constantly checked. The standard gases checked for are carbon dioxide and hydrogen sulphide, but different gases can be examined as well if there is a reason to suspect their prospective presence.
The techniques commonly in use will use visual and audible sensors if any noxious gases are detected while operators are doing the job on sludge removal within the confined spaces of tanks or vessels. These can be high density, bright flashing lights combined with loud alarms. There can be other alarm systems in use, such as vibrating devices for example, depending on the particular situation involved. Tank and vessel sludge removal is not normally a straightforward job. It calls for a high stress on basic safety for those involved. For that reason remote sludge removal systems are preferred, but regrettably are not always simple or feasible to use.