A 200-kilometre mineral pipeline proposed by Australian mining company SolGold has ignited fierce debate in Ecuador and Colombia, with experts warning that it could trigger the most severe mining-related environmental disaster in recent Latin American history.
The project, tied to the Cascabel copper-gold mine in northern Ecuador’s Mira River basin, would transport concentrated mineral slurry — comprised of powdered ore and water at a 60:40 ratio — from the mine site to the port of Esmeraldas.
The slurry contains copper, lead, cadmium, and other heavy metals.
Environmental observers fear spills, leaks, and failures along the route could devastate rivers, mangrove ecosystems, and coastal communities.
According to project documents, the Cascabel mine is expected to generate over 600 million tonnes of tailings, most of which will be discharged into dams in the Santiago and Mira river basins.
Tailings ponds are prone to leaks and failures; the 2019 Brumadinho dam collapse in Brazil killed 270 people and released millions of cubic metres of toxic mud into rivers, highlighting escalating global concerns about mine waste management.
The proposed slurry pipeline would cut across 18 parishes in northern Esmeraldas Province, crossing the Rioverde, Cayapas, Santiago, and numerous smaller rivers before reaching the Esmeraldas River.
Nearly 50 small estuaries — including the protected Esmeraldas River Mangrove Wildlife Refuge and the Manglares Cayapas-Mataje Ecological Reserve — would be placed at risk of contamination.
These habitats provide livelihoods for Afro-Ecuadorian and Indigenous communities through sustainable fishing and shellfish harvesting.
Marine scientists warn that contaminated sediments from the mine and tailings ponds will ultimately collect in mangrove ecosystems, threatening more than 80 kilometres of Ecuador and Colombia’s Pacific coastline.
These regions belong to the Chocó biogeographic corridor, one of the most biodiverse areas on Earth.
Though Ecuador would retain the fiscal revenues from the mine, experts say most environmental costs will spill into Colombia.
Tailings-contaminated waters are expected to reach the Mira and Santiago river basins, impacting over 500 kilometres of waterways on both sides of the border.
Colombia’s Cabo Manglares, Bajo Mira y Frontera National Park — nesting ground for sea turtles and a biodiversity hotspot — would receive much of the contaminated sediment.
Protected Awá Indigenous territories straddling the border will also be affected.
The contentious mine sits less than 20 kilometres from the Colombia border, a zone plagued by armed actors.
Authorities estimate at least five armed groups — including dissident FARC factions and drug-trafficking organisations — operate in the region.
The San Lorenzo police station bombing in 2018 and the killings of three Ecuadorian journalists that same year underscore how volatile the area remains.
SolGold argues that Cascabel could generate billions in export revenue, strengthen Ecuador’s foreign reserves, and provide thousands of jobs.
But local communities and environmental coalitions dispute whether these economic benefits outweigh the potential damage.
Opponents assert that Cascabel undermines decades of peacebuilding and cross-border cooperation efforts between Ecuador and Colombia.
The Ecuador-Colombia Binational Border Integration Plan — launched in 2014 — prioritised sustainability and biodiversity protection as pillars of coexistence.
Critics argue Cascabel would reverse this progress by driving inequality, conflict, and environmental degradation.
While the Ecuadorian government has endorsed SolGold’s exploration, environmental licensure remains pending.
Civil society organisations in both countries are calling for transnational environmental impact assessments and stronger oversight.
If approved, Cascabel will represent Ecuador’s largest mining venture to date, but also the single most disruptive environmental project in the Chocó-Andean region in living memory.