Södertörns Brandförsvarsförbund is an End User First Responder partner in the INGENIOUS project. SBFF is one of the largest fire and rescue organisations in Sweden with 10 municipalities within their district. They have 10 career stations (personnel 24/7), 3 “part time” stations with personal on watch at home and a few totally volunteer stations mainly on the islands in the archipelago and remote areas. Totally around 450 of staff. As a fire brigade in Sweden, they attend all sorts of incidents, not only fires but also car or train incidents, suicide, search and rescue on landslide or building collapses or incidents with hazardous substances.

Below is a description of a recent incident that was unusual both in type, size and over time, where INGENIOUS tools could come to help. It was a major fire in a huge illegal landfill active for three months. In addition to SBFF, the involved agencies include, but are not limited to: the National Board of Health and Welfare (Socialstyrelsen), the Swedish geotechnical Institute (SGI), the Swedish Civile Contingencies Agency (MSB), the Swedish Meteorological and Hydrological Institute (SMHI) and the Swedish Defense Research Agency (FOI). The estimated cost of this operation for SBFF is about 11 million SEK (approximately €1 million).

Background

On the 23^rd of December 2020, a fire started in an illegal landfill 30km south of Stockholm. The landfill pile was 140x70m and with a height between 5-10m when the fire started. The volume was measured by LIDAR scanning at the beginning of January and was then estimated to 31.000m³. Fire in landfill masses is often (and in this case) a relatively slow and low intensity fire on the outside. The main combustion happens deep inside the pile generating a huge amount of toxic gases (smoke).

An initial response was launched with the goal of stopping the spread by digging (with excavators) into the masses trying to get to the fire’s epicenter. Soon after the first responders reached the site it became clear that the area of the landfill was prone to landslide. The risk was assessed to be acute at the time and all fire personnel were ordered to withdraw from the area. In the absence of fire suppression, the fire spread over the following days to finally engulf the entire pile.

The fire produced a huge amount of smoke, affecting not only the nearby villages and farms but also more densely populated areas tens of kilometers away, including Stockholm city at times.

The delayed response

Due to the acute risk of landslide, it took almost one month to analyze the situation, find a workable solution and prepare an alternative response. Lengthy discussions with local, regional and national agencies took place. After an advanced geotechnical survey and detailed planning, the active response could resume. The only viable strategy was to cover the entire pile with sand. To achieve that, a construction company was contracted to move sand from a nearby sand quarry to the landfill. To do so, they used several excavators, bulldozers, and dumper trucks, 7 days a week, 12 hours a day.

Safety of personnel was priority number one, and therefore the amount of toxic smoke produced by the fire was a huge challenge to tackle. That, combined with other risks like an unpredictable ground for the machines, fire and heat had to be managed to be able to safely start working. A Safety team of fire & rescue personnel was set up to guarantee no one was injured. The Safety team equipped, trained, and supervised the machine operators to achieve a safe work environment.

To mitigate the risk of a landslide a counterbalance of sand had to be constructed around the landfill area. When that was in place, the actual covering of the pile could begin. The landfill was covered, and the smoke ceased after 4 weeks of hard work. 30.000m³ of sand was used in the process.

Challenges

• Tracking and visualization of movement of staff and vehicles in a low visibility environment – risk of collision & who is where if something happens?
• Gas monitoring in the smoke plume. How toxic is the smoke? The ability to constantly monitor changes.
• Measuring the volume of the pile (and the change of volume over time)
• Visual (and other sensors) monitoring of the event from a safe distance (UAS)
• Tactical planning in a dynamic environment (COP)
• Risk of landslide due to dynamic changes in load by diminishing material (burnt off) and additional load due to huge amounts of sand to cover the landfill.

Aftermath

Even when the landfill now is covered, it is still burning slowly inside. It is estimated to take up to a year for the masses to cool down to normal temperatures. But even so, the problems and challenges are still present. The nature around the landfill is of national interest and very sensitive to pollution. The remaining waste and burnt material are known to be toxic after the fire. Rainwater might wash out substances and cause damage to the surrounding area. Hence, the masses have to be taken care of in the nearby future in some way. However, it is up to the local and regional environmental agencies to handle the aftermath.

https://www.google.com/maps/@59.0982882,17.7881069,483m/data=!3m1!1e3

Ties to the INGENIOUS project

SBFF is involved in several Horizon 2020 projects which are developing future tools for first responders such as INGENIOUS. In general terms, fire and rescue responses are over within an hour or up to a few hours and complex tools and systems that require input from their users is not manageable as fast decisions are needed and there is little time to interact with a digital support system. However, in situations like the one described we can see huge advantages. 

We see the following advantages of tools that are being developed within INGENIOUS that could have helped us during the incident:

• Better and continuous areal imagery through UAV
• More targeted continuous monitoring of smoke plume spread and analysis of toxicity
• Possibility to measure temperature inside the landfill using UAG in order to estimate spread and initial locations
• Possibility to measure volume of landfill over time through UAG or similar.
• Faster and more accurate situation awareness reports on site and for the command centre and even for politicians and central national agencies, for better response and better communication with the affected public (residents in the near area)