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16 de Agosto del 2023
Lectura: 25 minutos
16 de Agosto del 2023
Investigación y textos: Manuel Novik. Fotos y video: Luis Argüello. Infografías: Jazmina Ojeda / PlanV
Ecuador: Dangerous tailings ponds surrounding the country's largest mine have no controls

The Quimi tailings dam was built on the edge of the river. The dump has a height of 30 meters approximately. Photos: Luis Argüello

The largest industrial mining project in the country's history will exploit a copper deposit until 2049. The second largest mining waste containment dam in the world is being built at Mirador. The poor waste management by the Chinese consortium has earned it sanctions and observations from the State.

Ecuador's first large-scale mine is being excavated in the heart of the Cordillera del Condor, a highly biodiverse mountain range in the Amazon region. The project is in Zamora Chinchipe, the province bordering Peru. Access to the concession is via a winding highway in poor condition.

The open-pit project disposes of 98% of the rock material it processes. With more than 140,000 tons of rock processed per day, the deposit of the waste in gigantic dumps generates alerts. The mining dams, known as tailings dams, agglutinate a muddy mass with thousands of tons of soil, water and chemicals, products of metal processing.

The Mirador concession has two: Quimi and Tundayme. The first can store 7.5 million cubic meters of tailings, while the second has a capacity of 370 million cubic meters. In the latter, the second highest dam in the world is being built, which at 260 meters should ensure that the tailings remain in the valley in perpetuity and do not contaminate nearby areas.

The second highest dam in the world (265m) is being built at the Tundayme tailings dam. The settling towers, which will serve to filter the dam water, give an idea of how tall the structure will be. Photo: Manuel Novik


The oxidation ponds are located between the two tailings dams, in an area of high rainfall and steep hills.

Currently, the world's tallest dam is in Peru, at Freeport McMoran's Cerro Verde mining project, at 265 meters high, according to Global Tailings Portal.

The world's highest mining dam is in Arequipa, Peru. The Cerro Verde concession is operated by the US company Freeport-McMoRan.

The mining camp that houses the personnel is at the foot of these dams. There are several villages less than four kilometers away. A collapse of these infrastructures could cause a flood that could kill hundreds of people.

The most dramatic case of this type of disaster occurred just four years ago in Brumadinho, Brazil. In the middle of the day, while the workers were at work, an avalanche left no chance of escape. The collapse of the slope of a large tailings dam caused 75% of the tailings to flood the surrounding area in 10 seconds. There were 270 deaths and the village was buried.

In the tragedy, the waste traveled more than 600 kilometers and polluted the Atlantic Ocean. This disaster was of a static nature, i.e. there was no external factor that caused the events, and the causes of the disaster are still under investigation.

In Tundayme, the closest town to the project, the former president of the Decentralized Autonomous Government (GAD), Luis Urdiales, assures that they do not have a contingency plan in case something similar happens. Alarms, cameras, and a monitoring system would be required to alert the population in case an evacuation is necessary. Urdiales assures that the Ministry of Environment has not given them the budget to put together the plan.

Luis Urdiales was president of the Decentralized Autonomous Government of Tundayme. Photo: Manuel Novik


The effects are visible

The road that connects the mining project with the Amazon highway runs through a dozen villages that are in an area directly affected by the project.

Like an eaglet sheltering from the sun among the branches of a tree, Carlos Wilson Tendetza, shelters from the heat in his wooden house in the middle of his banana and cassava plantations. While he checks his phone, he watches the promises of the presidential candidates on social networks.

Carlos Wilson Tendetza lives in a wooden house on the edge of the highway. Several Tendetza families have been settled in the village of Yanua Kim for generations.  

In 2013, when the State signed the contract for this mine with Ecuacorriente SA (ECSA), the subsidiary of the Chinese consortium CRCC-Tongguan, former President Rafael Correa promised that this province, Zamora Chinchipe, would become the "richest in the country".

Carlos Wilson is one of eight siblings, one of them the late José Tendetza, who was an anti-mining leader murdered in 2014: according to the trial file he was intercepted shortly before reaching his community, strangled and his body was thrown into the Zamora River. The crime remains in impunity.

Several generations of the Tendetza live in Yanua Kim, a Shuar community of humble houses that have populated the area for several generations. Twelve other communities live on the poverty line along the road that connects the mining project with the Amazon highway.

Carlos Wilson tells us on site that he is opposed to mining. However, he admits that they have received a bus stop for their community and assistance for cocoa production from the mining company. In addition, one of his twelve children works for Ecuacorriente. In the company, his colleagues reproach him for his father's opposition to mining.

In this community no one goes to the Quimi River anymore. Tendetza says the water is contaminated. The residents use piped water from a nearby waterfall for drinking water. In summer, they face droughts that leave them without many opportunities to get water.

Carlos Wilson assures that at night the water smells bad and comes down with a foam that is not typical of the river. No one in his community uses this water source anymore.  

In 2018 the Ministry of Environment sanctioned the company for not complying with the Environmental Management Plan.  The skepticism about the quality of the water is subscribed by the former president of the GAD of Tundayme, which is a few minutes away from this Shuar community, "at first glance I can tell you that the water is contaminated, but the standards in the legislation are very permissible," says Urdiales. Tundayme has a treated water system that is distributed through pipes to the houses. But when suspicious, the villagers opt to buy bottled water to drink.

Four families are supplied by a hose that brings piped water from a nearby waterfall.

The Comptroller General of the State (CGE) indicated, in a special examination of the project in 2020, that the permissible limits for metal concentrations in the Tundayme, Quimi and Wawayme rivers were exceeded between 2009 and 2016. Elements such as arsenic, cadmium or mercury were found outside the tolerable limits. This according to audits conducted by the Ministry of Environment, which sanctioned the mining company in 2018. Furthermore, it said that the lack of actions by the Environmental authorities prevented the company from taking corrective measures.

Tundayme, a stop for workers

Tundayme is a parish located four kilometers from the mining project. Below, several mechanical shops and workshops for Ecuacorriente's labor force can be seen.

A town square is part of the infrastructure that the company has built in Tundayme. In addition, they have built roads, electricity infrastructure and buildings.

The gigantic mine does not rest. Hundreds of dump trucks enter and leave the concession 24 hours a day. In Tundayme, auto parts stores, mechanics, hostels, restaurants, laundromats and "gentleman's clubs" ( brothels) have set up shop to supply the company's mostly male workforce, which comes from various parts of the country. At lunchtime, the town is filled with yellow vests and jean jackets with reflective stripes with the Chinese flag on the sleeves.

Small businesses await the visit of the labor force. Along the main road of the town, the workers' trucks and the 4x4 cars with tinted windows of the executives stop to eat something as they pass. A Chinese man in sandals, shorts and a T-shirt gets out of one of the trucks and buys an ice cream to cool off in the heat. Company buses transport workers to and from the camp.

Outside of the hours when ECSA personnel are busy, Tundayme is a town that looks empty. The coliseum has a large sign with the initials of the company, which has sponsored the construction. Houses with rusted zinc roofs and clothes hanging on the terrace sit on the hillside. In several homes it is common to see parked dump trucks being driven by workers resting from their shift.

Tundayme looks empty except for the transit of workers at early or late hours of the day

About 1,000 people live in Tundayme. In the community there are many small businesses.  

"I would dare say that everyone has at least one family member in the project; there are even entire families that work there," says Urdiales, the former director. In addition to the 900 residents of the area, another 2,000 arrive every day, he says.

In Tundayme there are several places such as laundromats or restaurants that are operated by or for Chinese nationals

A Chinese citizen kills time on her cell phone while managing a grocery store.

In Tundayme, beer is sold to workers resting from their work shifts.

Several hostels have opened their doors in Tundayme to receive the company's workforce. Other such establishments look abandoned.

According to a Central Bank report, since the mine began operating in June 2019, 38 million tons of ore, i.e., the land from which copper is ultimately obtained, were mined. The figure was recorded up to September 2022, the date of the last bulletin report.


The projected benefits for the State from taxes and the concession, according to projections by the Ministry of Energy and the Central Bank, would be between $7,000 and $9,500 million, a figure similar to the total income to the Government Budget between January and May 2023. The report states that the mine will create more than 3,000 direct jobs and around 10,000 indirect jobs by the end of 2022. The State participates in 52% of the mineral exploitation benefits.

Signs around the project are often in Spanish and Chinese. Chinese nationals, usually in administrative or management positions, drive around the project in SUVs

The source of mining waste

To find the copper, the mining industry has developed a "purification" process. Of the total, only 2% has copper concentrate. A first 50% of excavation with explosives or sterile rock drills. Generally, this rock material is used to build the dams of the tailings dams.

The Geografía Crítica collective explains the process for the remaining 50%, which does contain copper. The rock goes through a crushing process until a kind of sand is obtained. This is then mixed with water and chemicals that help the metals separate from the sand and float. The surface layer is removed and then undergoes a dewatering process. Mirador has the first beneficiation plant in the country, where copper concentrate is obtained, which is then exported to the Asian country for further processing.

The remains are left with the chemicals added in the process, in addition to particles of heavy metals harmful to health such as cyanide, cadmium or chromium. On the other hand, the rock exposed after drilling naturally contains metals that can come into contact with water and air and produce sulfuric acid, an element that can contaminate water sources. Tailings by themselves are not toxic, but if they are not managed in an appropriate manner, they can cause health and environmental disasters.

According to the researcher of the Universidad Andina, William Sacher, at the end of the 30-year life of the project, 325'000,000 million tons of tailings will be generated, equivalent to four times the volume of the Panecillo hill in Quito, an iconic hill in the Ecuadorian capital. Sacher adds that the figure is comparable to the waste production of the city of Guayaquil for more than 400 years.

This is the size of the Panecillo hill. The waste generated by the project would be equivalent to four times this hill

The construction of dams

There are three main types of tailings dam construction: Upstream, Downstream and Central Line.

The first consists of dams of the same size that are stacked on top of each other in the direction of the tailings beach. This is the cheapest method because of the low amount of resources required. It is also the most risky in the event of an earthquake because the wet tailings are below the dam. The method is also more susceptible to flooding.

In Ecuador there is a ministerial agreement issued by the Ministry of Energy that expressly prohibits the use of this method.

The second method is the safest and most expensive. It consists of the construction of an increasingly larger dike in the opposite direction to the waste beach. This method reduces the possibility of seepage and increases the tightness between the dikes.

The third method is a middle ground in terms of both cost and safety, as it leaves wet tailings below the dam. This method is allowed in Ecuador only in cases where the morphology of the site allows favorable stability conditions.

The Ministry of Energy assures that for the Quimi tailings dam the downstream method was used in the first phase and the central line method in the second phase. In total, the deposit currently reaches a height of 30 meters. The Ministry assures that the Tundayme tailings dam is being built downstream. For the latter, the riverbed was diverted and the canyon area was set aside to store the tailings.

But Steven Emerman, a researcher who was part of an E-Tech consulting firm report on the case, claims that the Quimi dam was built in violation of the ministerial agreement using the upstream method. The geophysicist visited the project site and conducted studies over years to determine that there were differences between the initial proposal and the final construction.

Researcher Steven Emerman holds an M.S. in Geophysics from Princeton University and a Ph.D. in Geophysics from Cornell University. Video capture

The researcher explains that in the downstream method, the initial dike is the smallest, over which additional, larger dikes are constructed in the opposite direction of the tailings. At the Quimi tailings dam, the location of the edge is at the border with the road and the river, so the construction of additional dams downstream would be impossible. "Energy gives an answer based on designs, not on what actually exists in the field," he argues.

Emerman says the state has not provided information on the method used for the Tundayme tailings dam. But the researcher points out that the projected height of the 260-meter dam is illegal in China itself.

According to the ministry, the Quimi dam has about 1 million cubic meters free in case of suspension of operations at the Tundayme dam. The Ministry assures that the dams are constantly being cleaned and drained. 

Researcher Emerman assures that the initial dam is built on the edge of the Quimi tailings dam, so the downstream method could not have been used, as claimed by the Ministry of Energy. Below, the Quimi River flows a few meters from the tailings dam.

Ecuacorriente refused to grant an interview to this portal on this issue. Nor did they agree to answer written questions about the methodology used for the construction of the tailings dams at the site.

Imminent collapse?

The E-Tech report states that Mirador is a worst-case scenario for a tailings disaster: it combines high levels of seismicity, high rainfall, high topographic relief, high dam heights, among other factors. According to Emerman, a collapse at Mirador is not only probable but imminent. He assures that sooner or later there will be seismic activity or heavy rains and that the infrastructure of the project is not prepared to resist, not only until the end of the operation in 2049, but in the long term. After the closure of the mining operations, the tailings will remain on site in perpetuity.

The researcher assures that the company has increased tailings storage capacity and has obtained permits to operate without government oversight, "there is no way I can emphasize how dangerous this situation is. I don't know of any country that allows this, that says, yes, you have the permit and figure out along the way what you do with the tailings."

Emerman's statements are related to the observations of the Comptroller's Office. The control entity pointed out that the company built the explosives plant without authorization and therefore the details of the products manufactured there are unknown.

In addition, construction of the tailings dams began without the approval of technical feasibility by Energy. According to CGE, there was also no control of the waste generated in the project by the Provincial Environmental Directorate. 


E-Tech sent requests for information to the Ministries of Environment and Energy that were denied by the State due to a confidentiality clause. The consulting firm has requested international organizations to take measures so that the State releases information that is public. The National Assembly also requested information but it was not provided either.

According to another 2019 study by Steven Emerman, the Quimi dam was built at a 45-degree angle, with a slope of one meter vertical by one meter horizontal, despite the fact that the Environmental Impact Study had specified a slope of one meter vertical by two meters horizontal. Institutions such as the U.S. Army Corps of Engineers or the European Commission recommend slopes of one by five or even one by three due to internal erosion processes that increase the risk of weakening the structure.

The Ministry of Energy states that the slope of the Quimi dam has an angle of 29.74 degrees and was built with a slope of one meter vertical by 1.75 meters horizontal. In the case of the Tundayme dam, it assures that it will have an angle of 18 degrees once its construction is completed.


According to the E-Tech report, in 2007 EcuaCorriente's own consultants, Knight-Piésold, assigned a dam failure category of "Very High" to the Quimi dam.

In 2018, David Dene, a United Nations expert on Harmony with Nature, and Juan Pablo Sáenz, a Quito-based lawyer, requested precautionary measures in the Constitutional Court to prevent inadequate infrastructure from being used for waste containment. The two citizens claim that a catastrophe is inevitable given the natural conditions of the site.

The petitioners do not dispute that the company has the permits, they claim that in other disasters of the same type in Brazil, Canada and Israel, the companies were in compliance, but they warn that there will certainly be seismic events and floods so the disaster is "imminent".


The case at the IACHR

In 2013, a group of social organizations filed a complaint with the Inter-American Commission on Human Rights for environmental rights violations related to the construction of the Mirador project. The international action was brought by CONAIE, CONFENIAE, Fundación Pachamama, Acción Ecológica, INREDH, the Human Rights Center of PUCE and several affected local residents. The plaintiffs and the State have already presented their arguments and are awaiting a resolution.

The plaintiffs claim that there are severe environmental damages, forced displacements, impacts on ancestral territories of the Shuar nationality and violations of collective rights such as the right to territory and the right to free, prior and informed consultation. Mario Melo, one of the lawyers sponsoring the case, told this portal that "there are 70 displaced families in Tundayme, the town of San Marcos was disappeared and its inhabitants have not been repaired".

Mario Melo is the dean of the Faculty of Jurisprudence of the Catholic University. Video capture

The jurist maintains that "what used to be an Amazon forest is now a gigantic hole that has changed land use". The lawyer maintains that in Mirador there are water sources tributary to the Zamora River, a connection of the waters of the Andes and the Amazon River. "We are talking about transnational damage," he says.

Among the towns affected by the project are the communities of San Antonio, Santa Cruz, Quimi Valley, El Quimi, Machinaza Alto, Chuchumbletza, Remolino 2 and Tundayme. In addition to the Shuar communities of Yanúa Kim, Churuwia, Etsa and San Carlos de Numpaim.

Valle del Quimi is a low-income community. The village is in the foothills of the mining project.

A world filled with tailings

The mining industry is a waste-generating machine. At Mirador, only 2% of the material removed is copper concentrate, the rest is unusable. Tons that become mountains of slurry tailings that are stored in perpetuity.

There are between 29,000 and 35,000 mine tailings dumps globally, whether from active, inactive or abandoned concessions, according to World Mine Tailings Failures. The organization records that from 1960 to 2023 there were 156 catastrophes resulting from the collapse of these infrastructures. 85% of the disasters are reported in active dams.


Large-scale mining involves the removal of entire mountains and produces some of the largest infrastructures ever built. According to a Reuters report, industrial mining began in the 1800's in Japan and France, giving way to a mining boom in the United States and Canada from 1881 throughout the 20th century.

After World War II, there was an exponential increase worldwide and South Africa and Australia entered the mining map. In the 1970s the industry reached South America, but it was not until the 2010s that the largest number of dams were built worldwide.a

Despite advances in mining technology, seven significant disasters have occurred since 2014 in the United States, Israel, China, Canada, Mexico and twice in Brazil. The consequences of these accidents are devastating. For example, the Mount Palley case in Canada involved the discharge of 25 million cubic meters of tailings, the equivalent of 20,000 Olympic-sized swimming pools, according to UN Environment and GRID Arendal.

This is what the Mount Polley tailings dam in Canada looked like before and after the collapse that discharged 25 million cubic meters of waste. Photos: The Narwhal

There is no database that compiles all of the world's debris dumps. One of the most comprehensive records was initiated by the Church of England in 2019 after the Brumadinho (Brazil) disaster. The Anglican institution together with 114 other investors founded the Investor Safety in Mining and Tailings Safety Initiative (IMTSI). With more than $20 billion of assets managed by mining companies, the shareholders initiated a process of accountability to prevent an accident of this magnitude from happening again.

Although the Church of England is under-reporting, 100 of the world's largest mining companies have provided information on the use of 1,800 tailings dams. Of this record, 50% of the dams are inactive or abandoned, that is, the mining operations there have ended.

Forty-two percent of the dams were built using the upstream method, 30% were built using the downstream method. The rest are distributed over at least five different methods, such as single stage, shaft or pile. Although most Chinese and Indian companies did not respond to the consortium, the registry reports that at least one-third of the world's tailings facilities have stability problems.

This story was produced with support from Earth Journalism Network.

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