Types of Confined Spaces and their Hazards

Confined spaces are not like any other ordinary workplace, and being within them can cause injuries and fatalities. The Canadian Centre for Occupational Health and Safety notes that precautions must be made to make confined spaces safe before workers enter. For the workers who brave the hazardous conditions of confined spaces, it’s vital to know just what sort of risks could be faced.

What are confined spaces?

A confined space is any enclosed space that carries with it a risk of death or serious injury from dangerous conditions or hazardous materials. These are areas that are not designed or purposed for human occupancy. Confined spaces generally have restricted entrances and exits, and despite their name, they’re not necessarily small.

Types of confined spaces

Confined spaces can exist both above and below ground. Some examples of confined spaces include:

  • Storage tanks and digesters
  • Sewers
  • Silos
  • Vats
  • Pipes
  • Wells
  • Tunnels
  • Ship holds
  • Subcellars
  • Cold storage rooms
  • Ducts
  • Access shafts
  • Manholes

A full list is difficult to provide, because some spaces that you may not consider hazardous can become confined spaces when work is being carried out within them, or during construction. Depending on the particular environment of a confined space, workers may be faced with one or a combination of hazards.

Lack of oxygen

Certain soils can react with oxygen in the air, thereby reducing the amount of oxygen available for workers operating within the confined space. Groundwater mixed with chalk and limestone can also produce carbon dioxide and displace breathable air.

Within the hold of a ship or a freight container, the cargo on board can react with air inside the space and reduce the amount of oxygen. Rust that forms within steel containers and tanks can also impact the amount of clean air available for workers.

Hazardous gases

Dangerous gases, fumes, and vapour can build up within sewers and manholes because of the variety of contaminants present. Pipework that contains these contaminants can also move poisonous gases into connected tanks or vessels. Gases may also leak into ditches and pits from contaminated land such as landfills and oil fields.

Welding activities or the use of volatile solvents and adhesives can also emit dangerous gases into a confined space. Sometimes the residue from previously-used products will emit vapours as well.

Solids and liquids

Substances that can suddenly fill a confined space pose a risk to workers within. Solids that are free-flowing, like grain or flour, can sometimes partially solidify. When that happens, a blockage is formed that could collapse unexpectedly.

Heat and fire

Confined spaces may not have adequate ventilation, which can lead to heat buildup within the space, and dangerous increases in body temperature for workers. Sometimes increases in temperature may be the result of work being carried out within the space. Flammable materials and vapours that exist within some confined spaces also poses the risk of fire and explosions.

The hazards facing workers within confined spaces are real, and that’s why it’s important for employers to understand and mitigate the risks involved. That allows employers to get the best from their workers, while giving workers the ability to do their jobs safely.

Wessuc plans out each confined space entry to ensure the work is completed in the safest manner possible. All crew members receive the necessary confined space training which enables us to react quickly to any circumstances that may arise during a clean out project.

Contact us at info@wessuc.com to learn more about our trained professionals and how we can help you.

Aeration Tank Efficiency

Given the rising costs of energy in our province, it is important that aeration tanks that process waste water run as efficiently as possible. Whether at the municipal or industrial level, it is estimated that electricity typically accounts for about 30% of the cost in wastewater treatment. This article will examine what is needed to ensure that that you are getting the most out of your aeration tank.

Aeration System Components

Essentially aeration systems can be divided into three main parts including: airflow generation, airflow distribution and aeration control. To obtain maximum aeration tank efficiency, each of these parts must be operating at optimal levels.

Types of Blowers

As technology has improved, more efficient types of blowers have been developed. For example, systems that use straight oxygen (O2) require significantly less energy than those that use air. Furthermore, it is essential that the right size and horsepower blowers for the tank be used.

Using multiple blowers is also beneficial because it reduces the chance that a system-wide pumping failure might occur. As old air blowers fail, companies and municipalities may choose to replace them with O2 blowers. While they can be replaced all at once, doing so requires a large amount of capital so it often makes more sense financially to replace them over time to gain greater efficiency.

Process Piping

The piping system is another critical component for helping determine the efficiency of the aeration tank. If the pipes are too small, blowers with more horsepower may be required. If the pipes are too large, the system may become too difficult to control.

Equipment Components

Additionally, each of the components of the aeration tanks must meet certain standards to ensure efficiency. These components include air control valves, airflow meters and DO meters.

  • Air Control Valves – Valve size should be large enough that they can operate when they are 30-70% open. They should be installed downstream of airflow meters in order to reduce the amount of possible disturbances in the airflow.
  • Airflow Meters – There are several different types of airflow meters on the market and all work well as long as they have been properly installed. These must be placed a minimum distance either upstream or downstream of a disturbance. The manufacturer’s guidelines on this distance should be adhered to for optimal efficiency.
  • DO Meters – DO Meters have become standard in municipal wastewater plants. These optical-based meters are popular because of their reliable readings and also because they require only a minimal amount of maintenance. These meters should be placed between halfway and two-thirds down the aeration control basin.

Maintenance and Cleaning

Finally, even if you have all the best components, you won’t optimize your efficiency without proper maintenance and regular cleaning. As tanks fill up with sludge, they become less efficient but regular cleaning can help restore them.

The efficiency of an aeration tank comes down to both the components that are used as well as its ongoing maintenance. If you would like to improve the efficiency of your municipal or industrial tank, contact Wessuc today. A member of our team would be happy to meet you for a consultation and discuss possible ways to improve your efficiency.

The Benefits of Using Vacuum Trucks

It frequently amazes our clients how the Wessuc team is able to clean industrial tanks and reservoirs and haul away waste materials using our super vac trucks. There are many benefits however to using vacuum trucks for this purpose.

While there are a variety of types of vacuum trucks and attachments all designed for specific purposes and industries, these vehicles do share certain similarities. They are equipped with high-powered vacuum and hydro-excavation systems which are designed to clean out various types of industrial tanks, lagoons and municipal water infrastructure. These vehicles are also equipped with debris tanks of their own for hauling away materials for safe disposal.

The benefits of vacuum trucks for this purpose are as follows:


There are a variety of makes and models of vacuum trucks on the market today that are equipped for a variety of cleaning jobs for both wet and dry debris. These vehicles can haul away large amounts of hazardous material as they are equipped with water tanks that can hold up to 1,500 gallons and debris tanks that can hold up to 2,000 gallons.


Employing vacuum trucks and experienced crews for cleaning tanks and reservoirs is one of the fastest and safest ways to get the job done. At Wessuc, our crews are fully trained and certified and our equipment is always well maintained and equipped for the job.

Operators undergo extensive training in Confined Space Entry, WHMIS, First Aid, Electrical Awareness, Traffic Protection and more.


The most convenient way to have tanks cleaned is for it to be done onsite by experienced professionals with the right equipment. Our vacuum trucks require minimal water and our technicians are proficient at what they do.

Moving tanks and other equipment around is inconvenient at the best of times, but our fully mobile cleaning units save you the hassle.

Cost Savings

Since cleaning can be done onsite, it eliminates many of the costs that would come along with it otherwise. The logistics of each site are assessed ahead of time before the cleaning crew arrives with the super vac truck.

Before their arrival, safety issues are addressed and a plan is developed which in turn mitigates the risk of any unforeseen costs.

Operations Efficiency

Since tanks and other reservoirs are cleaned onsite, that means less downtime for the business or municipality. The amount of time that tanks or vessels are out of operation is reduced as there is no transporting them back and forth. They can be put back into operation as soon as the cleaning process is complete.

Further efficiency is gained by the fact that waste from the industrial tanks is captured directly in the debris tanks of the trucks making it ready for safe transport and disposal.

Whether you operate a business that uses industrial tanks, or whether you work for a municipality and are sourcing service providers to assist you with your cleaning needs and transporting materials, the team at Wessuc can help.

Contact us today for more information.

How Do I Know if My Tanks and Confined Spaces are Clean?

Proper cleaning of storage and processing tanks is essential for efficient and safe operation. Over time, these tanks can get clogged up with dirt and debris, thereby decreasing the volume that the tank can hold and causing mechanisms such as pumps and heat exchangers to work harder and less efficiently. Similarly, lagoons also require regular cleaning to ensure they too remain efficient.

The question then, is how do you know your tanks and confined spaces are actually getting clean? Essentially it comes down to experienced personnel and the right technology.

Technology to get the job done right

To ensure that tanks are properly cleaned, you need to work with an industrial tank cleaning service that has the proper technology. At Wessuc, we have the technology to work with both municipal and industrial clients.

Using a dual vacuum system, we are able to maintain continuous suction. This allows the tank to drain faster meaning that it can get back into operation sooner. Using our unique dewatering unit, we can rid tanks and other confined spaces of a variety of sludges including those generated by chemical processing, wastewater treatment and various types of manufacturing. This can be done on site using very little energy.

The system works by causing a vacuum to form inside the tank. The liquid is pulled through a filter and a polymer may be added to the water to help with the separation of liquids and solids. The solids form a “cake” which is then removed from the drum with a blade.

Highly trained personnel

Of course, even the best technology is often limited by the expertise of those who use it. The job of tank cleaning has the potential to pose complex safety issues. Because of these facts, Wessuc uses only highly professional and well-trained tank cleaning crews.

Prior to their arrival, we conduct an investigation of the site to analyse any safety issues that may arise. This allows us to fully plan out the job before crews arrive on site.

Our crews have experience cleaning a wide variety of equipment and confined spaces including lagoons, water filters, water towers, aeration tanks, scum pits and more.

Other factors to consider

Meeting environmental regulations is also extremely important. In fact, many companies strive not just to meet regulations but to exceed them. At Wessuc, we work hard to ensure that these high standards are met.

Oftentimes, removed residuals can be beneficially used on farmland. But to ensure it is suitable, debris such as plastic, rags and hair must be removed. For this reason, we custom built a mobile screening unit which our cleaning crews use to physically screen sludge to remove this type of debris.

In other instances, we are treating wastewater that will eventually be returned to lakes, rivers and streams. This is done through a series of filtering stages, use of micro-organisms and disinfecting in order to make the water safe to reintroduce back into the environment.

If your company uses tanks or other types of confined spaces, having the right team and technology on your side for proper cleaning is essential. To learn more about our process, contact us today.