 Just five years after the Ikea Illumina tailings dam failure in Hungary, similar images of communities flooded by contaminated mud would appear in Brazil. The failure of the fundal tailings dam would release 43 million cubic meters of iron ore tailings over an area of 668 kilometers of water courses from the Dolce River to the Atlantic Ocean. It would be known as Brazil's worst environmental disaster and would hold a mirror up to the country's mining industry but sadly lessons wouldn't be learnt quick enough. As such I'm going to rate this disaster here eight on my patented plain difficult disaster scale but only here five on the legacy scale as well we'll get onto that a bit later on. The Germano Mine Complex is based in Mariana, Minas, Giraes, Brazil. The site operated by San Marco SA which is a Brazilian mining company founded in 1977. The company is a joint venture between Brazilian Vale and English Australian BHP. The tailings dams in question at the site were used in conjunction with iron ore mining. An industry which for every usable ton of iron ore concentrates around 2.5 to 3 tons of waste tailings are created. These waste products need to be stored and that necessitates the use of storage ponds held back by a regular subject on this channel a tailings dam. Whilst we're here let's look at the process that creates this much waste product. Iron ore is vital in the production of steel obviously a massive important material for building of pretty much everything. The old one's mind is run through a process of crushing grinding and classification. During this waste materials such as sand and other undesirable matter are screened and either run through crushing again or sent to tailings storage areas. The process continues during concentration of the ore where it is hydro cyclone to separate out slimes and a removal of silica. The separated slimes are also sent to the tailings storage. Once the iron is taken out it is floated and magnetic or gravity separated before being filtered after which it is dried and turned into pellets for use in the production of steel. But that is a really brief explanation and the process is far more complex in reality but let's get back to the main subject of the video the tailings and its disposal in the form of storage. Tailings ponds are useful in draining away the moisture from waste products which then they can be stacked on top of another allowing for relatively efficient use of space. The Germano mining complex was no different and it employed this type of storage for its own waste created on site. The tailings storage area was started in 2008 and was intended to contain a total of 79.6 million cubic meters of fine tailings slime and around 32 million cubic meters of sandy tailings over a 25 year lifespan. The two types of tailings had different properties and as such had to be managed individually which greatly influenced the design of the dam. The sand deposits were transported in a slurry and consisted of silt sized particles which allowed water to drain away rather quickly after being deposited but were not the most stable as they were loose and easily displacable. The slimes were also transported as a slurry but were more compressible and permeable compared to the sand. The design of the tailings was a drain stack variety. The concept was to progressively stack the sands behind a starter dam with the slimes retained behind the sand stack. The starter dam would be raised on top of the sands using an upstream style construction once structurally stable. The area of the sands between the dam and the slimes is rather aptly named the beach. This type of dam has one big flaw and that is the fact that the structure is lifted and built upon the uncompacted sand which if not monitored and maintained properly to keep dry can result in disaster. To prevent static liquefaction three methods were used in the design. First was the comprehensive drainage system underneath the starter dam. The second was concrete drainage channels under the left and right abutments and finally keeping the beach at around 200 meters to prevent moisture from the slimes undermining the foundations of the starter dam. It is thought that the allowable height increase per year is around 5 meters but the dam at Fundow would be a victim of its own success. As stated earlier the project was to last 25 years but by just seven years after its beginning the dam was holding back 56.4 million cubic meters more than half its expected capacity. But throughout its life the dam was blighted with issues relating to drainage construction defects resulting in water management errors and saturation of the sand tailings. An internal erosion event happened in 2009 and the intended 200 meter sand beach width was not being adhered to with slimes getting as close as 60 meters from the dam crest during 2011 and 2012. After structural failure of the concrete gallery beneath the left abutment emergency measures were implemented in 2013 it was decided to realign the dam on the left shoulder by moving it behind the section of the gallery to be filled with concrete. This brought the crest closer to the slimes which would reduce the structural integrity of the dam. Originally the realignment was only to be for a short while but would continue until 2015 which leads us on to the disaster. At around half past 3pm on the 5th of November 2015 a leak was discovered on the dam. Attempts to produce the water level were not effective as failure occurred around 50 minutes later. Around 43 million cubic meters of tailings were released down the Santarium river valley. The toxic tidal wave which was 10 meters at its highest overflowed the Santarium and swept through Benito Rodriguez obliterating the village. The small community was only accessible by unpaved roads and post-disaster rescue efforts were severely hindered. The toxic flood continued down the Gao Axio and Dolce rivers eventually reaching the Atlantic Ocean 620 kilometers down river. The flood killed 19 people displaced 600 families and at least 400,000 people had their water supply disrupted. The environmental impact was truly shocking with around 11 tons of fish being killed hundreds of hectares of forest were destroyed and multiple cultural monuments feeding the brunt of the destruction. All of these effects impacted the local economy and general standard of living for the communities around the area with food and water shortages. Interruption of mining activity severely affected employment in 37 villages and cities and a general ban on fishing and agriculture added salt to the wound. This meant that people had fewer ways to earn money or even get food for themselves. But what was the cause of the disaster? We know that the fundale dam was questionable at best throughout its short working life but what made November 2015 the tipping point? A panel was set up by the Brazilian government to follow Samaco's own investigation into the failure state of the dam. During the investigation documents were leaked hinting that the company were well aware of the structural issues of the modified dam and that collapse was very likely. The information dated back to 2013 around the same time that the emergency realignment of the left abutment was undertaken. The company ordered investigation panel released their findings in 2016 and the failure point is not much of a surprise. It was found that liquefaction within loose saturated sands located at the left abutment started the disaster. This was caused by slimes under the sands weakening the structure due to less than 200 meters between slimes and starter dam. This process eventually resulted in the sands becoming unstable at which point liquefaction was triggered and the dam breached. If the drainage hadn't failed in 2013 necessitating the realignment of the left abutment then the disaster would never have happened which brings us on to the main cause, improper construction of those vital drains. Samaco's activities were suspended after the disaster and were ultimately fined 20 billion dollars which is just under 5 billion US dollars. But that wasn't the whole cost as compensation still had to be paid out to all those affected. This ran the company another few billion dollars. Now I mentioned right at the start of this video that although this was one of the worst it was definitely not one of the last tailings down failures in Brazil. As only a few hours drive away another similar disaster would happen just four years later. This video is a plain difficult production. All videos on the channel are creative commons attribution share alike licensed. Plain difficult videos are produced by me John in a sunny south-eastern corner of London UK. Help the channel grow by liking commenting and subscribing. Check out my twitter for all sorts of photos and odds and sods as well as hints on future videos. I've got patreon and youtube membership as well if you fancy supporting the channel financially. And all is left to say is thank you for watching.