Though it might not be obvious at first, sewers and manholes, like anything else, need to be maintained and cleaned in order to function properly. Think about it: the grime, sludge, sewage, and debris that build up on a manhole can cause a number of problems. You might find the manhole difficult to open or to seal up. This might create hazards for workers using the manhole. You need to keep them clean.
Generally, there are two different entities that might need manhole cleanup: municipalities with their own sewage systems, and industries with large enough sewage systems to require manholes. In either case, cleanup and maintenance crews will employ similar tactics.
First, consider that sewage systems are inherently damp areas, and that cleaning them by hand is not a good option for a variety of reasons we hope are obvious. The use of conventional cleaning machines is also inappropriate. In light of this, plumbing and sewage companies have adopted a simple but creative strategy – the use of high pressure water.
The work starts at the most upstream tract of the sewer. The team will then work their way down, employing high pressure water to clean the manhole and the sides of the sewer from all sludge and debris. Downstream areas are only touched once all the sewers upstream of them are cleaned. Roots and grease will be removed, and large debris is removed without being allowed to flow with the sewage. Manholes are, of course, cleaned before the sewers downstream of them; it makes sense to start at the openings.
For municipal cleanings, the contractor cleaning the sewer will generally use water supplied by the City’s fire hydrants. For industrial cleanings, other arrangements may be necessary.
Generally, the contractor won’t simply clean the manhole and adjacent sewers during the process – they’ll inspect these areas as well. Whether or not the inspection occurs before, during, or after the cleaning depends heavily on the type of work being done. No matter which way they’re done, inspections are important. They allow the contractor and the owner of the sewer and manhole to nip potential problems in the bud, and for both parties to establish preventive measures should they be necessary to curb future problems.
One of the biggest potential consequences of manhole and sewer cleaning is blowback. This is the result of high pressure running through the system, which could lead to foul smells or sewage backup flowing through fixtures rapidly. Contractors will use a variety of methods to mitigate blowback, but it’s advised that you close all toilets and plug sinks to avoid blowback. Residents of the City of Winnipeg can find more information here.
Industrial clients can get more information about security measures and protocol by discussing the cleaning with their contractor. We offer industrial plumbing services in Winnipeg, so if your company needs manhole cleanup and maintenance, get in touch with us. We’ll discuss your particular situation and needs in greater detail that we can on this blog.